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Identify some of the important advantages of shape-casting processes

(1) Complex part geometries are possible (2) Some casting operations are net shape processes, meaning that no further manufacturing operations are needed to accomplish the final part shape (3) Very large parts are possible (4) They are applicable to any metal that can be melted (5) Some casting processes are suited to mass production

Why should turbulent flow of molten metal into the mold be avoided?

(1) It accelerated formation of oxides in the solidified metal (2) It causes mold erosion of gradual wearing away of the mold due to impact of molten metal

What are some of the limitations and disadvantages of casting?

(1) Limitations on mechanical strength properties (2) Porosity (3) Poor dimensional accuracy (4) Safety hazards due to handling of hot metals (5) Environmental problems

What are some factors that affect the fluidity of a molten metal during pouring into a mold cavity?

(1) Pouring temperature above the melting point (2) Metal alloy composition (3) Viscosity of the liquid metal (5) Heat transfer to the surroundings

A branched molecular structure is stronger in the solid state and more viscous in the molten state than a linear structure for the same polymer: (a) true or (b) false?

(a)

Degree of polymerization is which one of the following: (a) average number of mers in the molecule chain; (b) proportion of the monomer that has been polymerized; (c) sum of the molecule weights of the mers in the molecule; or (d) none of the above?

(a)

Diamond is the hardest material known? (a) true or (b) false

(a)

Of the three polymer types, which one is the most important commercially: (a) thermoplastics, (b) thermosets, or (c) elastomers?

(a)

Of the three polymer types, which one is the most important commercially? (a) thermoplastics, (b) thermosets, or (c) elastomers

(a)

Polystyrene (without plasticizers) is amorphous, transparent, and brittle: (a) true or (b) false?

(a)

The strength and hardness of steel increases as carbon content (a) increases or (b) decreases

(a)

The strength and hardness of steel increases as carbon content (a) increases or (b) decreases?

(a)

Which of the following best characterizes the structure of glass-ceramics: (a) 95% polycrystalline, (b) 95% vitreous, or (b) 50% polycrystalline?

(a)

Which of the following metals is noted for its good electrical conductivity (one best answer)? (a) copper, (b) gold, (c) iron, (d) nickel, or (e) tungsten?

(a)

Which of the following metals is noted for its good electrical conductivity (one best answer): (a) copper, (b) gold, (c) iron, (d) nickel, or (e) tungsten?

(a)

Which one of the following elements is the most important alloying ingredient in steel: (a) carbon, (b) chromium, (c) nickel, (d) molybdenum, or (e) vanadium?

(a)

Which of the following is the most important cast iron commercially? (a) ductile cast iron, (b) gray cast iron, (c) malleable iron, or (d) white cast iron

(b)

Which of the following plastics has the highest market share: (a) phenolics, (b) polyethylene, (c) polypropylene, (d) polystyrene, or (e) polyvinylchloride?

(b)

Which one of the following comes closest to expressing the chemical composition of clay: (a) Al2O3, (b) Al2(Si2O5)(OH)4, (c) 3AL2O3-2SiO2, (d) MgO, or (e) SiO2?

(b)

Which one of the following is generally the most porous of the clay-based pottery ware: (a) china, (b) earthenware, (c) porcelain, or (d) stoneware?

(b)

Which one of the following is the chemical formula for the repeating unit in polyethylene: (a) CH2, (b) C2H4, (c) C3H6, (d) C5H8, or (e) C8H8?

(b)

Which one of the following metals has the lowest density: (a) aluminum, (b) magnesium, (c) tin, or (d) titanium?

(b)

Which one of the following metals has the lowest density? (a) aluminum, (b) magnesium, (c) tin, or (d) titanium

(b)

Ferrous metals include which of the following (two correct answers): (a) aluminum, (b) cast iron, (c) copper, (d) gold, and, (e) steel?

(b) cast iron (e) steel

Glass products are based primarily on which one of the following minerals? (a) alumina, (b) corundum, (c) feldspar, (d) kaolinite, or (e) silica

(e)

10.14 The empirical relationship that determines total solidification time in casting is known as which one of the following: (a) Bernoulli's theorem, (b) Chvorinov's rule, (c) continuity law, (d) flow curve, (e) Hooke's law, or (f) Ohm's law?

9. What is the difference between a process layout and a product layout in a production facility?

A process layout is when you group similar activities together according to the process or function they perform. A product layout arranges activities in a line according to the sequence of operations for a particular product or service.

There are various types of patterns used in sand casting. What is the difference between a split pattern and a match-plate pattern?

A split pattern is a pattern that consists of two pieces; a match-plate pattern consists of the two split patterns attached to opposite sides of a plate.

In which of the following properties do plastic parts often compare favorably with metals (two best answers): (a) impact resistance, (b) resistance to ultraviolet radiation, (c) stiffness, (d) strength, (e) strength-to-weight ratio, and (f) temperature resistance?

Answer. (a) and (e).impact resistancestrength-to-weight ratio

Which of the following are sections of a conventional extruder barrel for thermoplastics (three best answers): (a) compression section, (b) die section, (c) feed section, (d) heating section, (e) metering section, and (f) shaping section?

Answer. (a), (c), and (e).compression sectionfeed section, metering section

Sand casting is which of the following types: (a) expendable mold or (b) permanent mold?

Answer. (a).expendable mold

Total solidification time is defined as which one of the following: (a) time between pouring and complete solidification, (b) time between pouring and cooling to room temperature, (c) time between solidification and cooling to room temperature, or (d) time to give up the heat of fusion?

Answer. (a).ime between pouring and complete solidification

Shell molding is best described by which one of the following: (a) casting operation in which the molten metal has been poured out after a thin shell has been solidified in the mold, (b) casting process in which the mold is a thin shell of sand bonded by a thermosetting resin, (c) sand-casting operation in which the pattern is a shell rather than a solid form, or (d) casting operation used to make artificial sea shells?

Answer. (b). casting process in which the mold is a thin shell of sand bonded by a thermosetting resin,

In plaster mold casting, the mold is made of which one of the following materials: (a) Al2O3, (b) CaSO4-H2O, (c) SiC, or (d) SiO2?

Answer. (b).CaSO4-H2O

In a sand-casting mold, the V/A ratio of the riser should be (a) equal to, (b) greater than, or (c) smaller than the V/A ratio of the casting itself?

Answer. (b).greater

Investment casting is also known by which one of the following names: (a) fast-payback molding, (b) full-mold process, (c) lost-foam process, (d) lost-pattern process, or (e) lost-wax process?

Answer. (e). lost-wax process?

17.9 Describe the effect of strain rate in metal forming

As the strain rate increases, the material offers a greater resistance to deformation

Which one of the following materials has the highest modulus of elasticity: (a) aluminum, (b) diamond, (c) steel, (d) titanium, or (e) tungsten?

Diamond

17.3 Why is the term pressworking often used for sheet metal processes?

Due to the use of a press for all sheet metal processes

How does the designation scheme for magnesium work?

First 2 characters identify principal alloying elements, 2 numbers that indicates the amounts of the two alloying ingredients to nearest percent, and last symbol is a letter that indicates variation in composition

A Newtonian fluid is a fluid best defined by which one of the following: (a) its viscosity decreases as shear rate increases, (b) its viscosity decreases as temperature increases, (c) its viscosity increases as shear rate increases, (d) its viscosity increases as temperature increases, (e) its viscosity remains constant as shear rate changes, or (f) its viscosity remains constant as temperature changes?

Its viscosity remains constant as shear rate changes.

What is the basic difference between low-density and high-density polyethylene?

LDPE has a branched structure and is amorphous. HDPE is linear and highly crystalline. These differences account for HDPE having higher density, stiffness, and melting point.

The shear strength of a metal is usually (a) greater than or (b) less than its tensile strength?

Less than it's tensile strength S=0.7(TS)

Diff. btw. new shape processes & NEAR net shape processes?

NEAR net shape processes require subsequent machining

Does any polymer ever become 100% crystalline?

includes all metallic elements and their alloys that are not based on iron

Non Ferrous

Which one of the following types of stress strain relationship best describes the behavior of brittle materials such as ceramics and thermosetting plastics: (a) elastic and perfectly plastic, (b) elastic and strain hardening, (c) perfectly elastic, or (d) none of the above?

Perfectly elastic

The nylons are members of which polymer group?

Polyamides

precision

Precision is the degree to which the instrument gives repeated measurements of the same standard (repeatability).

Which one of the following is a machine used to perform extrusion: (a) forge hammer, (b) milling machine, (c) rolling mill, (d) press, (e) torch?

Press

Diff. btw. process & product layout in a production facility?

Process - grouped by functions. flexible, material moves in any direction, move storage space on assembly line Product - arranged in line according to place of operation, efficient, moves in ONE direction, less space on assembly line

Diff. between processing operation and assembly operation?

Processing - transform material to another state Assembly - joins two parts

Define availability

Proportion uptime of the equipment of equipment reliability A = ((T-tm)/T)X100 Ex. 100 hour period, 5 for repairs, 95 left. A = 95%

List the questions to which a checker will seek answers when he reviews a set of drawings.

Questions related to shape, size, form, orientation, and location.

o Design for assembly

Reduces scrap and reworking of units

A philosophy to balance the requirements of economy, environment, and society

Sustainable Manufacturing

A unit operation is defined as a single manufacturing step in the sequence of steps required to transform a starting material into a final part or product: (a) true or (b) false?

TRUE A unit operation it is a single step in the sequence of steps required to transform the starting material into a final product.

The term plant capacity refers to the maximum rate of production that a factory can achieve under assumed labor manning levels, hours of operation per week, and other operating conditions: (a) true or (b) false?

TRUE Plant capacity, or production capacity, defined as the maximum rate of production that a plant can achieve under assumed operating conditions. The operating conditions refer to number of shifts per week, hours per shift, direct labor manning levels in the plant, and so on.

What is the Antioch process?

The Antioch process refers to the making of the mold. The mold is 50% sand and 50% plaster heated in an autoclave and then dried. This mold has greater permeability than a plaster mold.

What does the degree of polymerization indicate?

The degree of polymerization indicates the average number of mers or repeating units in the polymer molecule.

What is the difference between vacuum permanent-mold casting and vacuum molding?

The difference is that for a vacuum permanent-mold, reduced air pressure from the vacuum in the mold is used to draw the liquid metal into the cavity, rather than forcing it by positive air pressure from below.

What are some of the factors that influence a polymer's tendency to crystallize?

The factors that influence a polymer's tendency to crystallize are the following: (1) only linear polymers can form crystals; (2) copolymers do not form crystals; (3) stereoregularity - isotactic polymers always form crystals, atactic polymers never form crystals, and syndiotactic polymers plasticizers inhibit crystal formation; and (6) stretching the polymer tends to promote crystallization.

What are the common forms of the reinforcing phase in composite materials?

The forms are: (1) fibers, (2) particles and flakes, and (3) an infiltrated phase in skeletal structures.

Name the two basic categories of casting processes.

The two categories are (1) expendable mold processes, and (2) permanent mold processes.

What are the two forms of sandwich structure among laminar composite structures? Briefly describe each.

The two forms are (1) foamed-core sandwich, in which the core is polymer foam between two solid skins; and (2) honeycomb, in which the core is a honeycomb structure sandwiched between two solid skins.

What properties determine the quality of a sand mold for sand casting?

The usual properties are (1) strength - ability to maintain shape in the face of the flowing metal, (2) permeability - ability of the mold to allow hot air and gases to escape from the cavity, (3) thermal stability - ability to resist cracking and buckling when in contact with the molten metal, (4) collapsibility - ability of the mold to give way during shrinkage

5. Name the three basic categories of materials.

Three basic categories of materials are metals, ceramics and polymers.

In the context of production equipment in a factory, the term availability is best defined by which one of the following: (a) downtime proportion, (b) hourly operating cost, (c) proportion of good products, (d) proportion uptime, or (e) utilization?

proportion uptime

An irregularity in the surface of the casting caused by erosion of the sand during pouring is called which one of the following sand casting defects: (a) penetration, (b) sand blow, (c) sand wash, or (d) scabs?

sand wash EXTRA -> - penetration: fluidity of the liquid metal is high, and penetrates into the sand mold or sand core. - sand blow: a balloon-shaped gas cavity caused by release of mold gases during pouring. - scabs: rough areas on the surface of the casting due to encrustations of sand and metal.

List some applications of high carbon steels (>0.50% C)

springs, cutting tools and blades; wear-resistant parts

basic size

theorectical size or prefereable size (e.g. +-)

The shear strength of a metal is commonly determined in which one of the following tests: (a) bending test, (b) compression test, (c) flexure test, (d) tensile test, or (e) torsion test?

torsion test thin-walled tubular specimen is subjected to a torque. As torque is increased, the tube deflects by twisting, which is a shear strain for this geometry.

bilateral tolerances

two-sided variation from the basic size i.e. 1.000+-.005

Solid solution alloying is the principal strengthening mechanism in high strength low alloy (HSLA) steels? (a) true or (b) false

(a)

Solid solution alloying is the principal strengthening mechanism in high-strength low-alloy (HSLA) steels: (a) true or (b) false?

(a)

The basic difference between low-density polyethylene and high-density polyethylene is that the latter has a much higher degree of crystallinity: (a) true or (b) false?

(a)

The fiber rayon used in textiles is based on which one of the following polymers: (a) cellulose, (b) nylon, (c) polyester, (d) polyethylene, or (e) polypropylene?

(a)

Which one of the following elements is the most important alloying ingredient in steel? (a) carbon, (b) chromium, (c) nickel, (d) molybdenum, or (e) vanadium

(a)

Which one of the following reinforcing geometries offers the greatest potential for strength and stiffness improvement in the resulting composite material: (a) fibers, (b) flakes, (c) particles, or (d) infiltrated phase?

(a)

Which one of the metallic elements is the most abundant on the earth: (a) aluminum, (b) copper, (c) iron, (d) magnesium, or (e) silicon?

(a)

Which one of the metallic elements is the most abundant on the earth? (a) aluminum, (b) copper, (c) iron, (d) magnesium, or (e) silicon?

(a)

Which one of the three polymer types does not involve cross-linking: (a) thermoplastics, (b) thermosets, or (c) elastomers?

(a)

Which of the following metals would typically be used in die casting (three best answers): (a) aluminum, (b) cast iron, (c) steel, (d) tin, (e) tungsten, and (f) zinc?

(a) aluminum, (d) tin, (f) zinc

Which one of the following engineering materials is defined as a compound containing metallic and nonmetallic elements: (a) ceramic, (b) composite, (c) metal, or, (d) polymer?

(a) ceramic

Which of the following polymers are normally thermoplastic (four best answers): (a) acrylics, (b) cellulose acetate, (c) nylon, (d) phenolics, (e) polychloroprene, (f) polyesters, (g) polyethylene, (h) polyisoprene, and (i) polyurethane?

(a), (b), (c), and (g)

Which of the following polymers are normally thermoplastic (four best answers)? (a) acrylics, (b) cellulose acetate, (c) nylon, (d) phenolics, (e) polychloroprene, (f) polyesters, (g) polyethylene, (h) polyisoprene, and (i) polyurethane

(a), (b), (c), and (g)

Which of the following materials are used as fibers in fiber-reinforced plastics (four best answers): (a) aluminum oxide, (b) boron, (c) cast iron, (d) E-glass, (e) epoxy, (f) Kevlar 49, (g) polyester, and (h) silicon?

(a), (b), (d), and (f)

Which of the following contains significant amounts of aluminum oxide (three correct answers): (a) alumina, (b) bauxite, (c) corundum, (d) feldspar, (e) kaolinite, (f) quartz, (g) sandstone, and (h) silica?

(a), (b), and (c)

Which of the following is the most important cast iron commercially: (a) ductile cast iron, (b) gray cast iron, (c) malleable iron, or (d) white cast iron?

(b)

In plaster mold casting, the mold is made of which one of the following materials: (a) Al2O3, (b) CaSO4-H2O, (c) SiC, or (d) SiO2?

(b) CaSO4-H2O

Traditional brass is an alloy of which of the following metallic elements (two correct answers): (a) aluminum, (b) copper, (c) gold, (d) tin, and (e) zinc?

(b) and (e)

(b) casting process in which the mold is a thin shell of sand bonded by a thermosetting resin

Glass ceramics are polycrystalline ceramic structures that have been transformed into the glassy state: (a) true or (b) false?

(b). Glass ceramics are glasses that have been transformed into a mostly crystalline form through heat treatment.

As the degree of crystallinity in a given polymer increases, the polymer becomes denser and stiffer, and its melting temperature decreases: (a) true or (b) false?

(b). Melting temperature increases with higher degree of crystallinity.

A steel with 1.0% carbon is known as which one of the following: (a) eutectoid, (b) hypoeutectoid, (c) hypereutectoid, or (d) wrought iron?

(c)

Anisotropic means which one of the following: (a) composite materials with composition consisting of more than two materials, (b) properties are the same in every direction, (c) properties vary depending on the direction in which they are measured, or (d) strength and other properties are a function of curing temperature?

(c)

Which of the following metals has the highest density: (a) gold, (b) lead, (c) platinum, (d) silver, or (e) tungsten?

(c)

Which of the following metals has the highest density? (a) gold, (b) lead, (c) platinum, (d) silver, or (e) tungsten

(c)

Which one of the following is fired at the highest temperatures: (a) china, (b) earthenware, (c) porcelain, or (d) stoneware?

(c)

Which one of the following materials is closest to diamond in hardness: (a) aluminum oxide, (b) carbon dioxide, (c) cubic boron nitride, (d) silicon dioxide, or (e) tungsten carbide?

(c)

Which one of the following casting metals is most important commercially: (a) aluminum and its alloys, (b) bronze, (c) cast iron, (d) cast steel, or (e) zinc alloys?

A production planning and control department accomplishes which of the following functions in its role of providing manufacturing support (two best answers): (a) designs and orders machine tools, (b) develops corporate strategic plans, (c) orders materials and purchased parts, (d) performs quality inspections, and, (e) schedules the order of products on a machine?

Mining is classified in which one of the following industry categories: (a) agricultural industry, (b) manufacturing industry, (c) primary industry, (d) secondary industry, (e) service industry, or, (f) tertiary industry?

Which one of the following casting processes is the most widely used: (a) centrifugal casting, (b) die casting, (c) investment casting, (d) sand casting, or (e) shell casting?

(d) sand casting

Given that Wm = weight of the molten metal displaced by a core and Wc = weight of the core, the buoyancy force is which one of the following: (a) downward force = Wm + Wc, (b) downward force = Wm - Wc, (c) upward force = Wm + Wc, or (d) upward force = Wm - Wc?

(d) upward force = Wm - Wc

The leading commercial synthetic rubber is which one of the following: (a) butyl rubber, (b) isoprene rubber, (c) polybutadiene, (d) polyurethane, (e) styrene-butadiene rubber, or (f) thermoplastic elastomers?

(e)

Which one of the following is not a common alloying ingredient in steel: (a) chromium, (b) manganese, (c) nickel, (d) vanadium, (e) zinc?

(e)

Which one of the following is not a common alloying ingredient in steel? (a) chromium, (b) manganese, (c) nickel, (d) vanadium, (e) zinc

(e)

Ceramic matrix composites are designed to overcome which of the following weaknesses of ceramics (two best answers): (a) compressive strength, (b) hardness, (c) hot hardness, (d) modulus of elasticity, (e) tensile strength, and (f) toughness?

(e) and (f)

Investment casting is also known by which one of the following names: (a) fast-payback molding, (b) full-mold process, (c) lost-foam process, (d) lost-pattern process, or (e) lost-wax process?

(e) lost-wax process

a,c

10.11 Two important relationships that determine the flow of molten metal in casting are which of the following (two correct answers): (a) Bernoulli's theorem, (b) Chvorinov's rule, (c) continuity law, (d) flow curve, (e) Hooke's law, or (f) Ohm's law?

10.12 Total solidification time is defined as which one of the following: (a) time between pouring and complete solidification, (b) time between pouring and cooling to room temperature, (c) time between solidification and cooling to room temperature, or (d) time to give up the heat of fusion?

10.13 During solidification of an alloy when a mixture of solid and liquid metals is present, the solid liquid mixture is referred to as which one of the following: (a) eutectic composition, (b) ingot segregation, (c) liquidus, (d) mushy zone, or (e) solidus?

10.7 In casting processes, a runner is which one of the following: (a) channel in the mold leading from the downsprue to the main mold cavity, (b) worker who moves the molten metal to the mold, or (c) vertical channel into which molten metal is poured into the mold?

11.12 Which of the following qualifies as a precision-casting process (two correct answers): (a) ingot casting, (b) investment casting, (c) plaster-mold casting, (d) sand casting, and (e) shell molding?

a,b,d

11.13 Which of the following are metals commonly cast in permanent mold casting (three best answers): (a) aluminum, (b) brass, (c) gold, (d) magnesium, (e) nickel, (f) steel, and (g) tungsten?

a,e

11.14 Which of the following casting processes are permanent mold operations (two correct answers): (a) centrifugal casting, (b) expanded polystyrene process, (c) sand casting, (d) shell molding, (e) slush

11.15 In hot-chamber die-casting machines, molten metal is poured into an unheated chamber from an external melting container, and a piston is used to inject the metal under high pressure into the die cavity: (a) true or (b) false?

a,d,f

11.16 Which of the following metals would typically be used in die casting (three best answers): (a) aluminum, (b) cast iron, (c) steel, (d) tin, (e) tungsten, and (f) zinc?

11.20 Cupolas are furnaces used to melt which of the following metals (one best answer): (a) aluminum, (b) cast iron, (c) steel, or (d) zinc?

11.21 A misrun is which one of the following defects in casting: (a) globules of metal becoming entrapped in the casting, (b) metal is not properly poured into the downsprue, (c) metal solidifies before filling the cavity, (d) microporosity, and (e) "pipe" formation?

11.22 An irregularity in the surface of the casting caused by erosion of the sand during pouring is called which one of the following sand casting defects: (a) penetration, (b) sand blow, (c) sand wash, or (d) scabs?

11.23 Which one of the following casting metals is most important commercially: (a) aluminum and its alloys, (b) bronze, (c) cast iron, (d) cast steel, or (e) zinc alloys?

11.9 Investment casting is also known by which one of the following names: (a) fast-payback molding, (b) full-mold process, (c) lost-foam process, (d) lost-pattern process, or (e) lost-wax process?

What percent of the U.S. GDP is accounted for by the manufacturing industries?

12%

The unit energy for melting and pouring for a certain casting metal = 1000 J/g, its density = 5.0 g/cm3, and the volume of the casting = 600 cm3 including riser and gating system. The total heat required to raise the temperature of the metal to the pouring temperature is closest to which one of the following?

3000 kJ.

A product's total manufacturing costs typically constitute what proportion of the product's selling price: (a) 10%, (b) 20%, (c) 40%, (d) 60%, or (e) 80%?

40%

What is a plasticizer?

A plasticizer is a chemical added to the polymer to make it softer and more flexible. It is often added to improve the polymer's flow characteristics for shaping.

What is a polymer?

A polymer is a compound comprised of long-chain molecules that consist of repeating units, called mers, connected end to end.

What is a terpolymer?

A terpolymer is a polymer with three different mer types. An example is ABS (acrylonitrile-butadiene-styrene) plastic.

What is the difference between an open mold and a closed mold?

An open mold is open to the atmosphere at the top; it is an open container in the desired shape which must be flat at the top. A closed mold has a cavity that is entirely enclosed by the mold, with a passageway (called the gating system) leading from the outside to the cavity. Molten metal is poured into this gating system to fill the mold.

A three-plate mold offers which of the following advantages when compared to a two-plate mold (two best answers): (a) automatic separation of parts from runners, (b) gating is usually at the base of the part to reduce weld lines, (c) sprue does not solidify, and (d) stronger molded parts?

Answer. (a) and (b).automatic separation of parts from runnersgating is usually at the base of the part to reduce weld lines

Which of the following riser types are completely enclosed within the sand mold and connected to the main cavity by a channel to feed the molten metal (two correct answers): (a) blind riser, (b) open riser, (c) side riser, and (d) top riser

Answer. (a) and (c).

The principal components of an injection molding machine are which two of the following: (a) clamping unit, (b) hopper, (c) injection unit, (d) mold, and (e) part ejection unit?

Answer. (a) and (c).clamping unitinjection unit

Which of the following processes are generally limited to thermoplastic polymers (two best answers): (a) blow molding, (b) compression molding, (c) reaction

Answer. (a) and (d).blow molding

Which of the following processes would be applicable to produce hulls for small boats (three best answers): (a) blow molding, (b) compression molding, (c) injection molding, (d) rotational molding, and (e) vacuum thermoforming?

Answer. (a), (d), and (e).blow moldingrotational moldingvacuum thermoforming

Which one of the following processes is used to produce glass tubing: (a) Danner process, (b) pressing, (c) rolling, or (d) spinning?

Answer. (a).Danner process

In sand casting, the volumetric size of the pattern is (a) bigger than, (b) same size as, or (c) smaller than the cast part?

Answer. (a).bigger than

The term encapsulation refers to which one of the following plastics shaping processes: (a) casting, (b) compression molding, (c) extrusion of hollow forms, (d) injection molding in which a metal insert is encased in the molded part, or (e) vacuum thermoforming using a positive mold?

Answer. (a).casting

In foundry work, a runner is which one of the following: (a) channel in the mold leading from the downsprue to the main mold cavity, (b) foundryman who moves the molten metal to the mold, or (c) vertical channel into which molten metal is poured into the mold?

Answer. (a).channel in the mold leading from the downsprue to the main mold cavity,

The upper half of a sand-casting mold is called which of the following: (a) cope or (b) drag?

Answer. (a).cope

Which of the following qualifies as a precision-casting process (two correct answers): (a) ingot casting, (b) investment casting, (c) plaster-mold casting, (d) sand casting, and (e) shell molding?

Answer. (b) and (c).(b) investment casting, (c) plaster-mold casting

Casting is a glassworking process used for (a) high production, (b) low production, or (c) medium production?

Answer. (b). Casting is used in glassworking for large components like giant telescope lenses in small lot sizes. It is a slow process for these large products.

Use of a parison is associated with which one of the following plastic shaping processes: (a) bi-injection molding, (b) blow molding, (c) compression molding, (d) Answer. (b).pressure thermoforming, or (e) sandwich molding?

Answer. (b). blow molding

In casting, a flask is which one of the following: (a) beverage bottle for foundrymen, (b) box which holds the cope and drag, (c) container for holding liquid metal, or (d) metal which extrudes between the mold halves?

Answer. (b).box which holds the cope and drag

Cupolas are furnaces used to melt which of the following metals (one best answer): (a) aluminum, (b) cast iron, (c) steel, or (d) zinc?

Answer. (b).cast iron

Besides helping to preserve the environment, the use of recycled glass as an ingredient of the starting material in glassmaking serves what other useful purpose (one answer): (a) adds coloring variations to the glass for aesthetic value, (b) makes the glass easier to melt, (c) makes the glass stronger, or (d) reduces odors in the plant?

Answer. (b).makes the glass easier to melt

For which one of the following reasons is a green mold named: (a) green is the color of the mold, (b) moisture is contained in the mold, (c) mold is cured, or (d) mold is dry?

Answer. (b).moisture is contained in the mold,

The two most common polymer foams are which of the following: (a) polyacetal, (b) polyethylene, (c) polystyrene, (d) polyurethane, and (e) polyvinylchloride?

Answer. (c) and (d).polystyrenepolyurethane

A riser in casting is described by which of the following (three correct answers): (b) gating system in which the sprue feeds directly into the cavity, (c) metal that is not part of the casting, (d) source of molten metal to feed the casting and compensate for shrinkage during solidification, and (e) waste metal that is usually recycled?

Answer. (c), (d), and (e).

Which of the following casting processes are expendable mold operations (four correct answers): (a) centrifugal casting, (b) die casting, (c) investment casting, (d) low pressure casting, (e) sand casting, (f) shell molding, (g) slush casting, and (h) vacuum molding?

Answer. (c), (e), (f), and (h).(c) investment casting,(e) sand casting,(f) shell moldingh) vacuum molding

If a glass part with a wall thickness of 5 mm (0.20 in) takes 10 minutes to anneal, how much time would a glass part of similar geometry but with a wall thickness of 7.5 mm (0.30 in) take to anneal (choose the one closest answer): (a) 10 minutes, (b) 15 minutes, (c) 20 minutes, or (c) 30 minutes?

Answer. (c). The rule is that annealing time varies as the square of the wall thickness. That would indicate an annealing time of (0.30/0.20)2 = 2.25 times 10 minutes or 22.5 minutes. 20 minutes is closest.

Typical glass melting temperatures are in which of the following ranges: (a) 400°C to 500°C, (b) 900°C to 1000°C, (c) 1500°C to 1600°C, or (d) 2000°C to 2200°C?

Answer. (c).1500°C

Silica sand has which one of the following compositions: (a) Al2O3, (b) SiO, (c) SiO2, or (d) SiSO4?

Answer. (c).SiO2

A thermoforming mold with a convex form is called which one of the following: (a) a die, (b) a negative mold, (c) a positive mold, or (d) a three-plate mold?

Answer. (c).a positive mold

Which one of the following processes or processing steps is not applicable in glassworking: (a) annealing, (b) pressing, (c) quenching, (d) sintering, and (e) spinning?

Answer. (d). Sintering is used to cause bonding of particulate materials such as metal and ceramic powders.

Which one of the following casting processes is the most widely used: (a) centrifugal casting, (b) die casting, (c) investment casting, (d) sand casting, or (e) shell casting?

Answer. (d).sand casting

The function of the ejection system is which one of the following: (a) move polymer melt into the mold cavity, (b) open the mold halves after the cavity is filled, (c) remove the molded parts from the runner system after molding, or (d) separate the part from the cavity after molding?

Answer. (d).separate the part from the cavity after molding?

The charge in glassworking is which one of the following: (a) the duration of the melting cycle, (b) the electric energy required to melt the glass, (c) the name given to the melting furnace, or (d) the starting materials in melting?

Answer. (d).the starting materials in melting?

Answer. (d).upward force = Wm - Wc?

The parting line in injection molding is which one of the following: (a) the lines formed where polymer melt meets after flowing around a core in the mold, (b) the narrow gate sections where the parts are separated from the runner, (c) where the clamping unit is joined to the injection unit in the molding machine, or (d) where the two mold halves come together?

Answer. (d).where the two mold halves come together?

Which one of the following terms refers to the glassy state of a material: (a) crystalline, (b) devitrified, (c) polycrystalline, (d) vitiated, or (e) vitreous?

Answer. (e).vitreous

Chvorinov's rule states that total solidification time is proportional to which one of the following quantities: (a) (A/V)n, (b) Hf, (c) Tm, (d) V, (e) V/A, or (f) (V/A)2; where A = surface area of casting, Hf = heat of fusion, Tm = melting temperature, and V = volume of casting?

Answer. (f).(V/A)2

What is a cupola?

Answer. A cupola is a vertical cylindrical furnace equipped with a tapping spout near its base. Cupolas are used for melting cast irons.

What is a eutectic alloy?

Answer. A eutectic alloy is a particular composition in an alloy system for which the solidus and liquidus temperatures are equal. The temperature is called the eutectic temperature. Hence, solidification occurs at a single temperature, rather than over a temperature range.

What is a factory that performs casting operations usually called?

Answer. A foundry.

Which die-casting machines usually have a higher production rate, cold-chamber or hot-chamber, and why?

Answer. Hot-chamber machines are faster because cold-chamber die casting machines require molten metal to be ladled into the chamber from an external source. Ladling takes more time than injecting the molten metal into the die as in the hot-chamber operation.

Which die-casting machines usually have a higher production rate, cold-chamber or hot chamber, and why?

As the ladling of molten metal consumes more time as compared to injection inside the die, the hot chamber die-casting machine has a higher production rate

How does cylindricity differ from circularity

Circularity is a special case of cylindricity. Circularity refers to measurements taken in one place. Cylindricity applies to circularity over the entire surface.For example, the circularity can describe a circular end of a can and the cylindricity can describe the entire body of the can

What is clay, used in making ceramic products?

Clay most commonly consists of hydrous aluminum silicate; for example, kaolinite (Al2(Si2O5)(OH)4) is a common clay.

What are the most common metals used in die casting?

Common die-casting metals include zinc, tin, lead, aluminum, brass, and magnesium.

17.4 what is the difference between deep drawing and bar drawing

Deep- sheet metal operation, cut shaped parts as output. Bar- bulk deform, cylindrical parts of reduced diameter are output

What are some of the general defects encountered in casting processes? Name and briefly describe three.

Defects: misruns, microporosity, cold shuts, hot tearing, shrinkage cavity, and cold shots. Misruns: casting defect where castings solidify before being poured inside the mold. Microporosity: group of tiny voids located throughout the casting. Cold Shuts: It occurs in the absence of sufficient fusion between two metal that are flowing together.

Deformation processes include which of the following: (a) casting, (b) drilling, (c) extrusion, (d) forging, (e) milling, (f) painting, and, (g) sintering?

Deformation process: the material is initially a ductile solid then deformed to a desired shaped. ANS: Forging, Extrusion (metal that is pressed out and extruding from chamber)

How are a polymer's properties affected when it takes on a crystalline structure?

Density, stiffness, and melting temperature increase.

17.2 Extrusion is a fundamental shaping process. Describe it

Desired shape by allowing it to pass through an orifice

What does the term devitrification mean?

Devitrification is the transformation from the glassy state into a polycrystalline state.

Give some examples of commercial products which are laminar composite structures.

Examples given in Table 9.2 are automotive tires, honeycomb sandwich structures, fiber reinforced polymer structures such as boat hulls, plywood, printed circuit boards, snow skis made from fiber reinforced polymers, and windshield glass.

What are overhead costs in a manufacturing company?

Factory: maintenance, insurance, heat & light, etc. Corporate: sales, marketing, accounting, legal, etc.

Viscosity can be defined as the ease with which a fluid flows: (a) true or (b) false?

False Viscosity can be defined as the resistance with which a fluid flows:

Why are fillers added to a polymer?

Fillers are added to increase strength or simply to reduce the cost of the polymer.

What is flash in die casting?

Flash is a thin portion of metal at the exterior of a casting that results from molten metal being squeezed into the spaces between the die halves of the mold at the parting line, or into the clearances around the cores and ejector pins.

What is graphite?

Graphite is carbon in the form of hexagonal crystalline layers, in which covalent bonding exists between atoms in the layers, and the (parallel) layers are bonded by van der Waals forces, thus leading to highly anisotropic properties.

How do the properties of polymers compare with those of metals?

In general, polymers have lower strength, hardness, stiffness, density, and temperature resistance compared to metals. In addition, polymers have low electrical and thermal conductivity.

Explain the difference between hole-basis and shaft-basis systems

In hole-basis system the hole diameter of MMC is the reference dimension (basic sizes) or the stastive point for computation of all allowances and tolerances. In shaft-basis MMC of the shaft is that basic size

Which of the following qualifies as a precision-casting process: (a) ingot casting, (b) investment casting, (c) plaster-mold casting, (d) sand casting, and (e) shell molding?

Investment casting, plaster-mold casting

What is a cupola?

It is a vertical cylindrical shaped furnace supported by four legs. It is used in foundries for melting some bronzes and cast iron.

A methodology to minimize waste at all levels through assessment of each activities of a company

Lean Manufacturing

Properties of Magnesium

Lightest of the structural metals, easy to machine, is relative soft and lacks sufficient strength, strength-to-weight ratio is an advantage

What instruments would you use to measure linear distances

Linear: distances: steel rule, vernier caliper, micrometer, diffraction grating

2. What is the difference between measurement and gauging

Measurement gives a numerical value of a dimension of an object whereas gauging indicates whether or not the dimension of an object conforms (pass/fail) to specifications.

What are some of the general defects encountered in casting processes? Name and briefly describe three.

Misruns: castings that solidify before completely filling the mold cavity. Cold shuts: two portions of the metal flow together but there is a lack of fusion between them due to premature freezing. Cold shots: from splatters during pouring, causing the formation of solid globules of metal that become entrapped in the casting.

Why are aluminum and copper alloys unsuitable for use in hot chamber die casting?

Molten aluminum and copper alloys attack the metal pot used to hold the shot for the next casting. Over time, they would chemically attack and erode the die casting feeding mechanism.

Relative to the dimensions of the casting, the pattern that determines the geometry of the casting in expendable mold processes is usually made oversized, the same size, or undersized?

Option A: Oversized.

Particulate processing of metals and ceramics involves which of the following steps: (a) adhesive bonding, (b) deformation, (c) forging, (d) material removal, (e) melting, (f) pressing, and, (g) sintering?

Particulate process: the starting material is a powder, and the powders are formed and heated into the desired geometry. ANS: Pressing, Sintering

7. What are two subclasses of assembly processes? Provide an example process for each subclass.

Permanent joining process and mechanical fastening are two subclasses of assembly processes. Welding is considered permanent joining processes whereas threaded fasteners are mechanical assembly methods.

The shrinkage cavity that occurs in some castings resulting from restrictions in the amount of molten metal available to feed those cavities is called which one of the following by foundrymen?

Pipe.

Differences btw. primary, secondary, and tertiary industries? Give Ex.'s of each

Primary - cultivation & extraction of natural resources (forestry, agriculture, livestock & mining) Secondary - manufacturing industry (food processing, aerospace, automotive, etc.) Tertiary - service industry (education, health & medicine, banking)

1. What are the differences among primary, secondary and tertiary industries? Give an example of each category.

Primary industries develop and use natural resources, examples are agriculture and mining. Secondary industries use yields from primary industries and convert them into consumer goods, which include automotive, stationary, etc. Tertiary industries constitute the service sector of economy such as banking, and telecommunications etc.

Primary industry

High-volume production of assembled products is most closely associated with which one of the following layout types: (a) cellular layout, (b) fixed position layout, (c) process layout, or, (d) product layout?

Product layout

3. How are product variety and production quantity related when comparing typical factories?

Product variety and production quantity are inversely correlated in regards to factory operations.

4. How are product variety and production quantity related when comparing typical factories?

Product variety and production quantity are inversely correlated in terms of factory operations. If a factory's product variety is high, then its production quantity is likely to be low and vice-versa.

Identify some of the important properties of fiber-reinforced plastic composite materials.

Properties include high strength-to-weight ratio, high modulus-to-weight ratio, low density, good fatigue strength, good corrosion resistance, and low thermal expansion for many FRPs.

How does solidification of alloys differ from solidification of pure metals?

Pure metals solidify at a single temperature equal to the melting point. Most alloys (exceptions are eutectic alloys) start to solidify at the liquidus and complete solidification occurs at the solidus, where the liquidus is a higher temperature than the solidus.

The formation of new strain-free grains in a metal that has been heated to an elevated temperature is called which one of the following: (a) hot hardness, (b) recrystallization, (c) strain hardening, or (d) strain softening?

Recrystallization*

What does the term refractory mean?

Refractories are heat resistant ceramic materials. The term is sometimes also applied to metals that are heat resistant.

What is the primary mineral in glass products?

Silica, or silicon dioxide (SiO2).

The main ingredient in most glass products

Silica, silicon dioxide (SiO2)

Define unit operation

Single step operation while transformation starting material into final product

Which of the following casting processes are permanent mold operations: (a) centrifugal casting, (b) expanded polystyrene process, (c) sand casting, (d) shell molding, (e) slush casting, and (f) vacuum molding.

Slush casting, die casting, centrifugal casting

Soft vs. hard product variety

Soft - (small diff., most parts common, product line almost same, diesel car & petrol car) Hard - (large diff., most parts not common, product line almost fully different, car & cement truck)

What are the two main categories of alloys

Solid solutions and intermediate phases

There are various types of patterns used in sand casting. What is the difference between a split pattern and a match-plate pattern?

Split Pattern: 1) consist of two pieces. 2) they can manufacture a pattern with complex part geometries. 3) they do not use plate in middle of cope and drag. 4) they are cheaper. 5) accurate finishing is achieved. Match-Plate Pattern: 1) two split pieces are attached to either sides of a metal plate to form match-plate pattern. 2) mostly suitable for simple and ordinary geometries. 3) use a plate in the middle of cope and drag. 4) they cost more. 5) finishing achieved ini this pattern is more accurate compared to split pattern.

State the difference between straightness and flatness. Give examples.

Straightness is a special case of flatness. Straightness applies to only one element. Flatness applies to the entire surface. For example, a side view of a corner edge of a table could be described in terms of straightness and this table's top could be described in terms of flatness.

The flow curve describes the property of metals known as which one of the following: (a) ductility, (b) engineering strain, (c) fracture stress, (d) strain hardening, or (e) tensile strength?

Strain hardening

What properties determine the quality of a sand mold for sand casting?

Strength, permeability, thermal stability, collapsibility, reusability

a group of high-performance alloys designed to meet very demanding requirements for strength and resistance to surface degradation (corrosion and oxidation) at high service temperatures.

Superalloys

What is meant by the term superheat?

Superheat is the temperature difference above the melting point at which the molten metal is poured. The term also refers to the amount of heat that is removed from the molten metal between pouring and solidification.

6. What is surface roughness? What measures are used to specify it in engineering drawings? How is it measured?

Surface Roughness - small, finely spaced deviations from nominal surface determined by material characteristics and process that formed the surface. It is quantified by the vertical deviations of a real surface from its ideal form and is the arithmetic average deviation of the surface valleys and peaks. Roughness is expressed in terms of its height, its width, and its distance on the surface along which it is measured. Surface profilometer, microscope (SEM) etc are used to measure surface roughness.

How do thermoplastic elastomers differ from conventional rubbers?

TPEs are different in two basic ways: (1) they exhibit thermoplastic properties, and (2) their extensibility derives from physical connections between different phases in the polymer rather than cross-linking.

What are the three basic categories of polymers?

The categories are (1) thermoplastics, (2) thermosetting polymers, and (3) elastomers.

What is the chemical formula of ethylene, the monomer for polyethylene?

The chemical formula of ethylene is C2H4.

What is the continuity law as it applies to the flow of molten metal in casting?

The continuity law, or continuity equation, indicatesthat the volumetric flow rate is constant throughout the liquid flow.

Explain the difference between horizontal and vertical die-casting machines. Which is more popular?

The direction in the machine indicates the direction from which the metal is injected. Horizontal is injected from the side and vertical from the top. Horizontal is the most common type used in industry.

Copolymers can possess four different arrangements of their constituent mers. Name and briefly describe the four arrangements.

The four possible arrangements of the mers along the chain are (1) alternating, in which the mers repeat every other position; (2) random, in which the mers are in random order; (3) block, in which mers of each type group themselves into long segments along the chain; and (4) graft, in which mers of one type are attached as branches to a main backbone of mers of the other type.

What are some of the functions of the ingredients that are added to glass in addition to silica? Name at least three.

The functions of the additional ingredients include: (1) acting as flux (promoting fusion) during heating; (2) increasing fluidity in the molten glass during processing; (3) retarding devitrification, which is the tendency to crystallize from the glassy state; (4) reducing thermal expansion in the final product; (5) increasing the chemical resistance against attack by acids, basic substances, or water; (6) adding color to the glass; and (7) altering the index of refraction for optical applications (e.g., lenses).

Define technological processing capability

The group of manufacturing processes of available in that particular firm Mainly related to type of material Indicates firm specialization and the machinery installed in the firm Indicates the ability of the firm

Which one of the following is the correct definition of ultimate tensile strength, as derived from the results of a tensile test on a metal specimen: (a) the stress encountered when the stress-strain curve transforms from elastic to plastic behavior, (b) the maximum load divided by the final area of the specimen, (c) the maximum load divided by the original area of the specimen, or (d) the stress observed when the specimen finally fails?

The maximum load divided by the original area of the specimen

What are some of the operations required in sand casting after the casting is removed from the mold?

The operations include (1) trimming, in which the sprues, runners, risers, and flash are removed, (2) core removal, (3) surface cleaning, (4) inspection, (5) repair if needed, (6) heat treatment, and (7) machining.

What is the difference between a pattern and a core in sand molding?

The pattern determined the external shape of the cast part, while a core determines its internal geometry if the casting includes a cavity

What is the Antioch process?

The preparing of the permeable mold casting

What is the primary polymer ingredient in natural rubber?

The primary polymer ingredient in natural rubber is polyisoprene whose mer has the chemical formula C5H8.

What is the rule of mixtures?

The rule of mixtures applies to certain properties of composite materials; it states that the property value is a weighted average of the property values of the components, the weighting being by proportions of the components in the composite.

What is the composition of green sand in the green-sand molding process?

The sand is composed of silica sand, clay, and water.

Cross-linking (curing) of thermosetting plastics is accomplished by one of three ways. Name the three ways.

The three ways are (1) temperature-activated systems, in which elevated temperatures accomplish curing; (2) catalyst-activated systems, in which small amounts of a catalyst cause cross-linking; and (3) mixing-activated systems, in which two reactive components are mixed and curing occurs by their chemical reaction.

What are the three general factors that determine the properties of a composite material?

Three factors are given in the text: (1) the component materials; (2) the geometric shapes of the constituents - the reinforcing phase in particular - and the resulting structure of the material; and (3) the interaction of the phases.

clay products such as pottery, bricks, common abrasives, and cement

Traditional ceramics

What is the difference between the traditional ceramics and the new ceramics?

Traditional ceramics are based primarily on clay products (e.g., pottery, bricks) while new ceramics are more recently developed ceramics which are generally simpler in chemical composition (e.g., oxides, carbides).

How are traditional composites distinguished from synthetic composites?

Traditional composites have been used for decades or centuries; some of them are obtained from sources in nature, such as wood. Synthetic composites are manufactured.

The 3 basic categories of ceramics

Traditional, New ceramics, and glasses

What are some of the operations required in sand casting after the casting is removed from the mold?

Trimming, removal of core, surface cleaning, inspection, repair, heat treatment

A riser in a sand casting mold is a reservoir in the mold that serves as a source of liquid metal to compensate for shrinkage of the casting during solidification.

True

In hot-chamber die-casting machines, molten metal is poured into an unheated chamber from an external melting container, and a piston is used to inject the metal under high pressure into the die cavity: (a) true or (b) false?

True

The Antioch process is similar to plaster-mold casting but uses a mixture of sand and plaster to make the mold: (a) true or (b) false?

True

The expanded polystyrene casting process uses a mold of sand packed around a polystyrene foam pattern that vaporizes when the molten metal is poured into the mold: (a) true or (b) false?

True

Most hardness tests involve pressing a hard object into the surface of a test specimen and measuring the resulting indentation or its effect: (a) true or (b) false?

True Most hardness tests involve pressing a hard object into the surface of a test specimen and measuring the resulting indentation or its effect.

Viscoelasticity can be defined as the property of a material that determines the strain it experiences when subjected to combinations of stress and temperature over time: (a) true or (b) false?

True Viscoelasticity can be defined as the property of a material that determines the strain it experiences when subjected to combinations of stress and temperature over time.

What is the difference between true centrifugal casting and semi centrifugal casting?

True Centrifugal Casting: 1) cylindrical parts are produced by pouring molten metal into a rotating mold. 2) G-factors are around 60-80. 3) it is characterized by producing outline surfaces with no cores. Semi Centrifugal Casting: 1) solid castings are produced by pouring molten metal in a spun mold on a vertical axis. 2) G-factors are around 15. 3) it is characterized by producing internal surfaces with cores.

If engineering stress and true stress were measured simultaneously during a tensile test, which would have the higher value: (a) engineering stress or (b) true stress?

True stress

What is the relationship known as Chvorinov's rule in casting?

Tts = Cm(V/A)^2 Where Tts = total solidification time, Cm = mold constant, V = volume of casting, and A = surface area of casting

What are the general mechanical properties of ceramic materials?

Typical mechanical properties include high hardness, brittleness, and no ductility

The modulus of elasticity is also known as which one of the following: (a) elastic limit, (b) strain hardening exponent, (c) strength coefficient, or (d) Young's modulus?

Young's modulus

A typical production cycle time consists of which of the following elements (three best answers): (a) actual processing time, (b) inspection time, (c) rest breaks for the worker, (d) time to withdraw starting materials from storage, (e) tool fabrication time, (f) tool handling time, and (g) work handling time?

actual processing time, tool handling time, work handling time. EXTRA ->It might be argued that inspection time should also be included if the work part must be inspected in each cycle.

Which of the following metals would typically be used in die casting: (a) aluminum, (b) cast iron, (c) steel, (d) tin, (e) tungsten, and (f) zinc?

aluminum, tin, zinc

Straightness

an element of a surface or an axis is a straight line. A straightness tolerance specifies a tolerance zone within which the considered element must lie.

What instruments would you use to measure angles?

bevel protractor, sine bar, surface plates, angle gage blocks

One of the oldest metals known to mankind

copper

Which of the following casting processes are expendable mold operations: (a) centrifugal casting, (b) die casting, (c) investment casting, (d) low pressure casting, (e) sand casting, (f) shell molding, (g) slush casting, and (h) vacuum molding?

investment casting, sand casting, shell molding, vacuum molding

what dimensional entities are specified in engineering drawing besides size?

size, form, orientation, and location

Which one of the following is the name of the casting process in which molten metal is poured into a rotating mold to produce a tubular part: (a) centrifuge casting, (b) semicentrifugal casting, or (c) true centrifugal casting?

true centrifugal casting

What is the difference between true centrifugal casting and semicentrifugal casting?

true centrifugal casting, a tubular mold is used and a tubular part is produced. In semicentrifugal casting, the shape is solid; an example is a railway wheel. The mold is rotated so that centrifugal force is used to distribute the molten metal to the exterior of the mold so that the density of the final metal is greater at the outer sections.

upward force = Wm - Wc

Define manufacturing

"made by hand" OR The transformation of RAW MATERIAL INTO USEFUL GOODS by the application of physical and chemical processes

Name two basic mold types that distinguish casting processes

(1) Expandable molds (2) Permanent molds

Typical applications of steel?

1. Construction industry 2. Railways 3. Automobile industry 4. Home appliances

Definition of steel

All0y of iron & carbon

What is a chill in casting?

Answer. A chill is a heat sink placed to encourage rapid freezing in certain regions of the casting.

There are various types of patterns used in sand casting. What is the difference between a split pattern and a match-plate pattern?

Answer. A split pattern is a pattern that consists of two pieces; a match-plate pattern consists of the two split patterns attached to opposite sides of a plate.

Which casting process is the most important commercially?

Answer. Sand casting is the most important casting process.

items produced by continuous processes, such as sheet metal coil (almost), oil refinery

Continuous Products

o Design for manufacture

Design constrained to manufacturing area

The plastic region of the stress-strain curve for a metal is characterized by a proportional relationship between stress and strain: (a) true or (b) false?

False It is the elastic region that is characterized by a proportional relationship between stress and strain. The plastic region is characterized by a power function - the flow curve

Difference between special and general purpose production equipment?

General is flexible & adaptable, while special isn't

The transverse rupture strength is a property usually associated with which one of the following material types: (a) ceramics, (b) metals, (c) plastics, or (d) rubber?

Metals*

What is a ring gauge used for? What is a plug gauge? How is a snap gauge used to measure the diameter of a bar?

Ring gauge is used to gauge (inspect) shafts. Plug gauge is used to gauge(inspect) holes

These are highly alloyed steels designed for corrosion resistance

Stainless steels

What is a chaplet?

The metal pieces that support the core

What is flash in die casting?

The very thin metal portion at the outside of a casting

Perpendicularity

a surface, center plane, or axis at a right angle to a datum plane or axis

more recently developed ceramics based on oxides, carbides, etc., with better mechanical or physical properties than traditional ceramics

new ceramics

basic hole system

system where the minimum hole is taken as the basic size. allowance for each mating part is then assigned and tolerances are applied on both sides of, and away from, this allance

limits

the maximum and the minimum dimensions that are acceptable for a feature

metrology

the science of measurement

roundness

the surface of revolution where all points at the surface in a plane perpendicular to a common axis are equidistant from that axis. Consider the following roundness specification

tolerances

the total amount of variation permitted for a specific dimension. the difference b/n the upper and the lower limites

Concentricity

the variation of two cylinders from a common, or datum, axis

Identify the three sources of contraction in a metal casting after pouring

(1) Contraction of the molten metal after pouring (2) Solidification shrinkage during transformation of state from liquid to solid (3) Thermal contraction in the solid state

Diamond is the hardest material known: (a) true or (b) false?

(a)

Which of the following casting processes are permanent mold operations (three correct answers): (a) centrifugal casting, (b) die casting, (c) expanded polystyrene process, (d) sand casting, (e) shell molding, (f) slush casting, and (g) vacuum molding.

(a) centrifugal casting, (b) die casting, (f) slush casting

Properties and characteristics of the glass-ceramics include which of the following (two best answers): (a) efficiency in processing, (b) electrical conductor, (c) high thermal expansion, and (d) strong, relative to other glasses?

(a) and (d)

Which of the following alloying elements are most commonly associated with stainless steel (two best answers)? (a) chromium, (b) manganese, (c) molybdenum, (d) nickel, and (e) tungsten

(a) and (d)

Which of the following alloying elements are most commonly associated with stainless steel (two best answers): (a) chromium, (b) manganese, (c) molybdenum, (d) nickel, and (e) tungsten?

(a) and (d)

Which of the following ceramics are commonly used as abrasives in grinding wheels (two best answers)? (a) aluminum oxide, (b) calcium oxide, (c) carbon monoxide, (d) silicon carbide, and (e) silicon dioxide

(a) and (d)

Which of the following ceramics are commonly used as abrasives in grinding wheels (two best answers): (a) aluminum oxide, (b) calcium oxide, (c) carbon monoxide, (d) silicon carbide, and (e) silicon dioxide?

(a) and (d)

Which of the following are advantages of die casting over sand casting (four best answers): (a) better surface finish, (b) closer tolerances, (c) higher melting temperature metals, (d) higher production rates, (e) larger parts can be cast, and (f) mold can be reused?

(a) better surface finish, (b) closer tolerances, (d) higher production rates, (f) mold can be reused

In sand casting, the volumetric size of the pattern is (a) bigger than, (b) same size as, or (c) smaller than the cast part?

(a) bigger than

Which of the following processes start with a material that is in a fluid or semifluid state and solidifies the material in a cavity (two best answers): (a) casting, (b) forging, (c) machining, (d) molding, (e) pressing, and, (f) turning?

(a) casting (b) forging

A copolymer is a mixture of the macromolecules of two different homopolymers: (a) true or (b) false?

(b)

Among the thermosetting polymers, the most widely used commercially is which one of the following? (a) epoxies, (b) phenolics, (c) silicones, or (d) urethanes

(b)

Among the thermosetting polymers, the most widely used commercially is which one of the following: (a) epoxies, (b) phenolics, (c) silicones, or (d) urethanes?

(b)

As the temperature of a polymer increases, its density (a) increases, (b) decreases, or (c) remains fairly constant?

(b)

From which of the following ores is aluminum derived: (a) alumina, (b) bauxite, (c) cementite, (d) hematite, or (e) scheelite?

(b)

Plain carbon steels are designated in the AISI code system by which of the following: (a) 01XX, (b) 10XX, (c) 11XX, (d) 12XX, or (e) 30XX?

(b)

Plain carbon steels are designated in the AISI code system by which of the following? (a) 01XX, (b) 10XX, (c) 11XX, (d) 12XX, or (e) 30XX

(b)

The reinforcing phase is the matrix within which the secondary phase is imbedded: (a) true or (b) false?

(b)

For which one of the following reasons is a green mold named: (a) green is the color of the mold, (b) moisture is contained in the mold, (c) mold is cured, or (d) mold is dry?

(b) moisture is contained in the mold

Cupolas are furnaces used to melt which of the following metals (one best answer): (a) aluminum, (b) cast iron, (c) steel, or (d) zinc?

(b) cast iron

Which of the following qualifies as a precision-casting process (two correct answers): (a) ingot casting, (b) investment casting, (c) plaster-mold casting, (d) sand casting, and (e) shell molding?

(b) investment casting, (c) plaster-mold casting

Which of the following is typical of the starting work geometry in sheet metal processes: (a) high volume-to-area ratio or (b) low volume-to-area ratio?

(b) low volume-to-area ratio

Which one of the following materials is closest to diamond in hardness? (a) aluminum oxide, (b) carbon dioxide, (c) cubic boron nitride, (d) silicon dioxide, or (e) tungsten carbide

(c)

Which one of the following polymer types are most commonly used in polymer matrix composites: (a) elastomers, (b) thermoplastics, or (c) thermosets?

(c)

Which one of the three polymer types is not normally considered to be a plastic: (a) thermoplastics, (b) thermosets, or (c) elastomers?

(c)

Wood is which one of the following composite types: (a) CMC, (b) MMC, or (c) PMC?

(c)

Which of the following metals are used as the matrix metals in nearly all WC cemented carbides and TiC cermets (two correct answers): (a) aluminum, (b) chromium, (c) cobalt, (d) lead, (e) nickel, (f) tungsten, and (g) tungsten carbide?

Which of the following properties or characteristics are inconsistent with the metals (two correct answers): (a) good thermal conductivity, (b) high strength, (c) high electrical resistivity, (d) high stiffness, and (e) ionic bonding?

Which of the following properties or characteristics are inconsistent with the metals (two correct answers)? (a) good thermal conductivity, (b) high strength, (c) high electrical resistivity, (d) high stiffness, and (e) ionic bonding

Deformation processes include which of the following (two correct answers): (a) casting, (b) drilling, (c) extrusion, (d) forging, (e) milling, (f) painting, and, (g) sintering?

A misrun is which one of the following defects in casting: (a) globules of metal becoming entrapped in the casting, (b) metal is not properly poured into the downsprue, (c) metal solidifies before filling the cavity, (d) microporosity, and (e) "pipe" formation?

The chemical formula for polyisoprene in natural rubber is which of the following: (a) CH2, (b) C2H4, (c) C3H6, (d) C5H8, or (e) C8H8?

(d)

The predominant phase in the iron-carbon alloy system for a composition with 99% Fe at room temperature is which one of the following: (a) austenite, (b) cementite, (c) delta, (d) ferrite, or (e) gamma?

(d)

Which one of the following is the most common element in the earth's crust: (a) aluminum, (b) calcium, (c) iron, (d) oxygen, or (e) silicon?

(d)

Which one of the following metals has the lowest melting point: (a) aluminum, (b) lead, (c) magnesium, (d) tin, or (e) zinc?

(d)

Which one of the following metals has the lowest melting point? (a) aluminum, (b) lead, (c) magnesium, (d) tin, or (e) zinc?

(d)

Silica sand has which one of the following compositions: (a) Al2O3, (b) SiO, (c) SiO2, or (d) SiSO4?

(d) SiO2

Which of the following materials are not composites (two correct answers): (a) cemented carbide, (b) phenolic molding compound, (c) plywood, (d) Portland cement, (e) rubber in automobile tires, (f) wood, and (g) 1020 steel?

(d) and (g)

Which one of the following is a machine used to perform extrusion: (a) forge hammer, (b) milling machine, (c) rolling mill, (d) press, (e) torch?

(d) press

(d) product layout

Inventions of the Industrial Revolution include which one of the following: (a) automobile, (b) cannon, (c) printing press, (d) steam engine, or, (e) sword?

(d) steam engine

Glass products are based primarily on which one of the following minerals: (a) alumina, (b) corundum, (c) feldspar, (d) kaolinite, or (e) silica?

(e)

Particulate processing of metals and ceramics involves which of the following steps (two best answers): (a) adhesive bonding, (b) deformation, (c) forging, (d) material removal, (e) melting, (f) pressing, and, (g) sintering?

(f) pressing (g) sintering

What are the most common metals used in die casting?

(zinc, tin, lead, and sometimes magnesium)*

- Orders materials and purchased parts - Schedules the order of products on a machine

There are various types of patterns used in sand casting. What is the difference between a split pattern and a match-plate pattern?

- Split pattern: consists of two pieces, dividing the part along a plane where the two halves align. - Match-plate pattern: The two halves are to the opposite sides of a wood or metal plate.

What is the difference between true centrifugal casting and semicentrifugal casting?

- true centrifugal: molten metal is poured into a rotating mold to produce a tubular part. - semicentrifugal casting: produces solid castings instead of tubular parts.

What are some of the operations required in sand casting after the casting is removed from the mold?

1 Trimming: removing sprues, runners, risers, and flash 2 Removing the core 3 Surface cleaning 4 Inspection 5 Repair, if required 6 Heat treatment 7 Machining

5 categories of steel groups

1. Plain carbon steels 2. Low alloy steels 3. Stainless steels 4. Tool steels 5. Specialty steels

4 categories of shaping operations?

1. Solidification process 2. Particulate processing 3. Deformation process 4. Material Removal process

4 types of permanent joining processes used in assembly

1. Welding 2. Brazing 3. Soldering 4. Adhesive Bonding

10.1 Casting is a process in which molten metal flows into a mold where it solidifies in the shape of the mold cavity; the term casting also applies to the part that is made by this process: (a) true or (b) false?

c,d

10.10 Turbulence during pouring of the molten metal is undesirable for which of the following reasons (two best answers): (a) it causes discoloration of the mold surfaces, (b) it dissolves the binder used to hold together the sand mold, (c) it increases erosion of the mold surfaces, (d) it increases the formation of metallic oxides that can become entrapped during solidification, (e) it increases the mold filling time, and (f) it increases total solidification time?

10.15 According to the empirical relationship in the previous question, total solidification time is proportional to which one of the following quantities: (a) (A/V)n, (b) Hf, (c) Tm, (d) V, (e) V/A, or (f) (V/A)2; where A = surface area of casting, Hf = heat of fusion, Tm = melting temperature, and V = volume of casting?

10.16 Solidification shrinkage in casting is defined as which one of the following: (a) liquid contraction during cooling prior to solidification, (b) liquid contraction during cooling and solidification, (c) contraction during the phase change from liquid to solid, or (d) thermal contraction of the solidified casting during cooling to room temperature.?

10.17 Metal inserts in the walls of a sand mold cavity designed to remove heat from the molten metal more rapidly than the surrounding sand are called which one of the following: (a) external chills, (b) internal chills, (c) pipes, or (d) sprues?

c,d,e

10.18 A riser in casting is described by which of the following (three correct answers): (a) an insert in the casting that inhibits buoyancy of the core, (b) gating system in which the sprue feeds directly into the cavity, (c) metal that is not part of the casting, (d) source of molten metal to feed the casting and compensate for shrinkage during solidification, and (e) waste metal that is usually recycled?

10.19 In a sand-casting mold, the V/A ratio of the riser should be (a) equal to, (b) greater than, or (c) smaller than the V/A ratio of the casting itself?

10.2 A factory that performs casting processes is called which of the following (one best answer): (a) casting plant, (b) foundry, (c) ingot-making plant, (d) metal working plant, or (e) molding plant?

a,c

10.20 Which of the following riser types are completely enclosed within the sand mold and connected to the main cavity by a channel to feed the molten metal (two correct answers): (a) blind riser, (b) open riser, (c) side riser, and (d) top riser?

10.3 Sand casting is which of the following types of casting process: (a) expendable mold or (b) permanent mold?

10.4 The upper half of a sand-casting mold is called which one of the following: (a) cope, (b) drag, (c) flask, or (d) pattern?

10.5 In casting, a flask is which one of the following: (a) beverage bottle for workers who perform casting, (b) box which holds the cope and drag, (c) container for holding liquid metal, or (d) metal which extrudes between the mold halves?

10.6 The pattern that determines the geometry of the casting in expendable mold processes is usually made (a) oversized, (b) the same size, or (c) undersized relative to the dimensions of the casting?

10.8 The internal surfaces of a casting are determined during the casting process by means of which one of the following: (a) core, (b) gating system, (c) parting line, (d) pattern, or (e) sprue?

10.9 Heating a metal from room temperature to pouring temperature in a casting operation depends on all of the following properties except which one: (a) density, (b) heat of fusion, (c) melting temperature, (d) specific heat, or (e) thermal expansion?

11.1 Which one of the following casting processes is the most widely used: (a) centrifugal casting, (b) die casting, (c) investment casting, (d) sand casting, or (e) shell casting

11.10 In plaster mold casting, the mold is made of which one of the following materials: (a) Al2O3, (b) CaSO4-H2O, (c) SiC, or (d) SiO2?

11.11 The Antioch process is similar to plaster-mold casting but uses a mixture of sand and plaster to make the mold: (a) true or (b) false?

a,b,d,f

11.17 Which of the following are advantages of die casting over sand casting (four best answers): (a) better surface finish, (b) closer tolerances, (c) higher melting temperature metals can be cast, (d) higher production rates, (e) larger parts can be cast, and (f) mold can be reused?

b,d

11.18 Which of the following names are applied to a process in which a molten metal is poured into a heated lower die, and the upper die is closed to create the mold cavity only after solidification begins (two correct answers): (a) liquid-metal casting, (b) liquid-metal forging, (c) rheocasting, (d) squeeze casting, or (e) thixocasting?

11.19 Which one of the following is the name of the casting process in which molten metal is poured into a rotating mold to produce a tubular part: (a) centrifuge casting, (b) semicentrifugal casting, or (c) true centrifugal casting?

11.2 In sand casting, the volumetric size of the pattern is (a) bigger than, (b) same size as, or (c) smaller than the cast part?

11.3 Silica sand has which one of the following compositions: (a) Al2O3, (b) SiO, (c) SiO2, or (d) SiSO4?

11.4 For which one of the following reasons is a green mold named: (a) green is the color of the mold, (b) moisture is contained in the mold, (c) the mold is cured, or (d) the mold is dry?

11.5 Given that Wm = weight of the molten metal displaced by a core and Wc = weight of the core, the buoyancy force is which one of the following: (a) downward force = Wm + Wc, (b) downward force = Wm - Wc, (c) upward force = Wm + Wc, or (d) upward force = Wm - Wc?

c,e,f,h

11.6 Which of the following casting processes are expendable mold operations (four correct answers): (a) centrifugal casting, (b) die casting, (c) investment casting, (d) low pressure casting, (e) sand casting, (f) shell molding, (g) slush casting, and (h) vacuum molding?

11.7 Shell molding is best described by which one of the following: (a) casting operation in which the molten metal has been poured out after a thin shell has been solidified in the mold, (b) casting process in which the mold is a thin shell of sand bonded by a thermosetting resin, (c) sand-casting operation in which the pattern is a shell rather than a solid form, or (d) casting operation used to make artificial sea shells?

11.8 The expanded polystyrene casting process uses a mold of sand packed around a polystyrene foam pattern that vaporizes when the molten metal is poured into the mold: (a) true or (b) false?

Cemented carbides are what class of composites?

A cemented carbide is a cermet; although the cemented carbide industry does not generally think of cemented carbides as cermets, they fit within the definition.

What is a cermet?

A cermet is a composite material consisting of a ceramic and a metal. In the text, it is defined as a composite consisting of ceramic grains imbedded in a metallic matrix.

What is a copolymer?

A copolymer is a polymer made up of two different types of mers, such as ethylene and propylene.

What is a cupola?

A cupola is a vertical cylindrical furnace equipped with a tapping spout near its base.

What is a cupola?

A cupola is a vertical cylindrical furnace equipped with a tapping spout near its base. Cupolas are used for melting cast irons.

What is a eutectic alloy?

A eutectic alloy is a particular composition in an alloy system for which the solidus and liquidus temperatures are equal. The temperature is called the eutectic temperature. Hence, solidification occues at a single temperature, rather than over a temperature range.

What is a factory that performs casting operations usually called?

A foundry

What is a chill in casting?

A heat sink placed to encourage rapid freezing in certain regions of the casting

Describe the difference in mechanical properties as a function of temperature between a highly crystalline thermoplastic and an amorphous thermoplastic.

A highly crystalline TP retains rigidity during heating until just before its Tm is reached. An amorphous TP shows a significant drop in deformation resistance as its Tg as temperature is reached; it becomes increasingly like a liquid as temperature continues to increase.

What is a hybrid composite?

A hybrid composite is a fiber-reinforced PMC in which two or more fibers materials are combined in the FRP.

What is a whisker?

A whisker is a thin, hairlike crystal of very high strength.

Which of the following industries are classified as secondary industries (three correct answers): (a) beverages (b) financial services, (c) fishing, (d) mining, (e) power utilities, (f) publishing, and, (g) transportation?

A) beverages B) power utilities C) publishing

accuracy

Accuracy is both precision and the degree to which the measurement tallies with the original mark.

Implementation of lean principles on a broad scale; has Flexibility (quick response to market)

Agile Manufacturing

a mixture or compound of two or more elements, at least one of which is metallic

Alloy

Which one of the following materials has the highest hardness: (a) alumina ceramic, (b) gray cast iron, (c) hardened tool steel, (d) high carbon steel, or (e) polystyrene?

Alumina ceramic

used in various applications from abrasives to artificial bones

Alumina-aluminum oxide (AlO23)

Which of the following are metals commonly cast in permanent mold casting (three best answers): (a) aluminum, (b) brass, (c) gold, (d) magnesium, (e) nickel, (f) steel, and (g) tungsten?

Aluminium, magnesium, brass (copper-based alloy) EXTRA -> cast iron

What does the term advanced composites mean?

An advanced composite is a PMC in which carbon, Kevlar, or boron fibers are used as the reinforcing material.

What happens to an elastomer when it is below its glass transition temperature?

An elastomer becomes hard and brittle when its temperature is below its Tg.

What does the term anisotropic mean?

Anisotropic means that the properties of a material vary depending on the direction in which they are measured.

Answer. (a), (b), (d), and (f).better surface finishcloser toleranceshigher productionmold can be reused

Which of the following processes are associated with the production of plastic sheet and film (three correct answers): (a) blown-film extrusion process, (b) calendering, (c) chill-roll extrusion, (d) doctor blade method, (e) spinning, (f) thermoforming, and (g) transfer molding?

Answer. (a), (b), and (c).blown-film extrusion process,calendering,chill-roll extrusion

Answer. (a), (b), and (f).centrifugal castingdie casting,slush casting

Which of the following metals would typically be used in die casting (three best answers): (a) aluminum, (b) cast iron, (c) steel, (d) tin, (e) tungsten, and (f) zinc?

Answer. (a), (d), and (f).aluminum tin zinc

The forward movement of polymer melt in an extruder barrel is resisted by drag flow, which is caused by the resistance to flow through the die orifice: (a) true or (b) false?

Answer. (b). Drag flow is the forward motion of the melt caused by the Archimedian screw principle in the barrel. The resistance to forward flow is called back pressure flow.

In rotational molding, centrifugal force is used to force the polymer melt against the surfaces of the mold cavity where solidification occurs: (a) true or (b) false?

Answer. (b). It is the force of gravity in the doubly rotating mold that forces the polymer against the mold surfaces.

The press-and-blow process is best suited to the production of (narrow-necked) beverage bottles, while the blow-and-blow process is more appropriate for producing (wide-mouthed) jars: (a) true, or (b) false?

Answer. (b). It's the reverse.

Which one of the following casting metals is most important commercially: (a) aluminum and its alloys, (b) bronze, (c) cast iron, (d) cast steel, or (e) zinc alloys?

Answer. (c).cast iron

Answer. (c).metal solidifies before filling the cavity

Which of the following defects or problems is associated with injection molding (three correct answers): (a) bambooing, (b) die swell, (c) drag flow, (d) flash, (e) melt fracture, (f) short shots, or (g) sink marks?

Answer. (d), (f), and (g).flash short shot sink marks

A lehr is which of the following: (a) a lion's den, (b) a melting furnace, (c) a sintering furnace, (d) an annealing furnace, or (e) none of the above?

Answer. (d).an annealing furnace

During solidification of an alloy when a mixture of solid and liquid metals is present, the solid-liquid mixture is referred to as which one of the following: (a) eutectic composition, (b) ingot segregation, (c) liquidus, (d) mushy zone, or (e) solidus?

Answer. (d).mushy zone,

Identify some of the important advantages of shape-casting processes.

Answer. Advantages include (1) complex part geometries are possible; (2) some casting operations are net shape processes, meaning that no further manufacturing operations are needed to accomplish the final part shape; (3) very large parts are possible; (4) they are applicable to any metal that can be melted; and (5) some casting processes are suited to mass production.

What is the difference between an open mold and a closed mold?

Answer. An open mold is open to the atmosphere at the top; it is an open container in the desired shape which must be flat at the top. A closed mold has a cavity that is entirely enclosed by the mold, with a passageway (called the gating system) leading from the outside to the cavity. Molten metal is poured into this gating system to fill the mold.

What is a chaplet?

Answer. Chaplets are metal supports of various designs used to hold the core in place in the sand mold.

What is the relationship known as Chvorinov's rule in casting?

Answer. Chvorinov's rule is summarized: TTS = Cm(V/A)2, where TTS = total solidification time, Cm = mold constant, V = volume of casting, and A = surface area of casting.

What are the most common metals used in die casting?

Answer. Common die-casting metals include zinc, tin, lead, aluminum, brass, and magnesium.

What are some of the limitations and disadvantages of casting?

Answer. Disadvantages include (1) limitations on mechanical strength properties; (2) porosity; (3) poor dimensional accuracy; (4) safety hazards due to handling of hot metals; and (5) environmental problems.

What is flash in die casting?

Answer. Flash is a thin portion of metal at the exterior of a casting that results from molten metal being squeezed into the spaces between the die halves of the mold at the parting line, or into the clearances around the cores and ejector pins.

What are some of the general defects encountered in casting processes? Name and briefly describe three.

Answer. General defects include: (1) misruns, in which the casting solidifies before filling the mold cavity; (2) cold shuts, in which two portions of metal flow together but there is lack of fusion at the joint; (3) cold shots, where solid globules of cast metal become entrapped in the casting; (4) shrinkage cavity, which is a depression on the casting surface or an internal void in the casting caused by solidification shrinkage; (5) microporosity, which is a network of small voids throughout the casting caused by localized solidification shrinkage; and (6) hot tearing, which is a crack in the casting caused by a mold that does not yield to the metal during the early stages of solidification shrinkage.

What does heat of fusion mean in casting?

Answer. Heat of fusion is the amount of heat energy required to transform the metal from solid state to liquid state.

What is the difference between true centrifugal casting and semicentrifugal casting?

Answer. In true centrifugal casting, a tubular mold is used and a tubular part is produced. In semicentrifugal casting, the shape is solid; an example is a railway wheel. The mold is rotated so

How does solidification of alloys differ from solidification of pure metals?

Answer. Pure metals solidify at a single temperature equal to the melting point. Most alloys (exceptions are eutectic alloys) start to solidify at the liquidus and complete solidification occurs at the solidus, where the liquidus is a higher temperature than the solidus.

What is meant by the term superheat?

Answer. Superheat is the temperature difference above the melting point at which the molten metal is poured. The term also refers to the amount of heat that is removed from the molten metal between pouring and solidification.

What is the Antioch process?

Answer. The Antioch process refers to the making of the mold. The mold is 50% sand and 50% plaster heated in an autoclave and then dried. This mold has greater permeability than a plaster mold.

What is the continuity law as it applies to the flow of molten metal in casting?

Answer. The continuity law, or continuity equation, indicates that the volumetric flow rate is constant throughout the liquid flow.

What are some of the factors that affect the fluidity of a molten metal during pouring into a mold cavity?

Answer. The factors include (1) pouring temperature above the melting point, (2) metal alloy composition, (3) viscosity of the liquid metal, and (4) heat transfer to the surroundings.

What are some of the operations required in sand casting after the casting is removed from the mold?

Answer. The operations include (1) trimming, in which the sprues, runners, risers, and flash are removed, (2) core removal, (3) surface cleaning, (4) inspection, (5) repair if needed, (6) heat treatment, and (7) machining.

What is the difference between a pattern and a core in sand molding?

Answer. The pattern determines the external shape of the cast part, while a core determines its internal geometry if the casting includes a cavity.

Identify the three sources of contraction in a metal casting after pouring.

Answer. The three contractions occur due to (1) contraction of the molten metal after pouring, (2) solidification shrinkage during transformation of state from liquid to solid, and (3) thermal contraction in the solid state.

Name the two basic categories of casting processes

Answer. The two categories are (1) expendable mold processes, and (2) permanent mold processes.

Name the two basic mold types that distinguish casting processes.

Answer. The two mold types are (1) expendable molds and (2) permanent molds.

What properties determine the quality of a sand mold for sand casting?

Answer. The usual properties are (1) strength - ability to maintain shape in the face of the flowing metal, (2) permeability - ability of the mold to allow hot air and gases to escape from the cavity, (3) thermal stability - ability to resist cracking and buckling when in contact with the molten metal, (4) collapsibility - ability of the mold to give way during shrinkage of the solidified casting, and (5) reusability - can the sand be reused to make other molds?

Why should turbulent flow of molten metal into the mold be avoided?

Answer. Turbulence causes the following problems: (1) it accelerates formation of oxides in the solidified metal, and (2) it causes mold erosion or gradual wearing away of the mold due to impact of molten metal.

What is the difference between vacuum permanent-mold casting and vacuum molding?

Answer. Vacuum permanent-mold casting is a form of low-pressure casting in which a vacuum is used to draw molten metal into the cavity. Vacuum molding is sand casting in which the sand mold is held together by vacuum pressure rather than by a chemical binder. 11.7 What are the most common metals used in die casting? Answer. Common die-casting metals include zinc, tin, lead, aluminum, b

Turbulence during pouring of the molten metal is undesirable for which of the following reasons (two best answers): (a) it causes discoloration of the mold surfaces, (b) it dissolves the binder used to hold together the sand mold, (c) it increases erosion of the mold surfaces, (d) it increases the formation of metallic oxides that can become entrapped during solidification, (e) it increases the mold filling time, and (f) it increases total solidification time?

Answer: (c) and (d). (c) it increases erosion of the mold surfaces, (d) it increases the formation of metallic oxides that can become entrapped during solidification

What is one of the important applications of titanium nitride, as mentioned in the text?

As a thin coating on cutting tools to prolong tool life.

17.6 How does increasing temperature affect the parameters in the flow curve equation

As temperature increases, there is a subsequent decrease in flow stress

How does the designation scheme for copper work?

Based on the Unified Numbering System for Metals and Alloys (UNS)

8. Define batch production and describe why it is often used for medium-quantity production products.

Batch production is a technique where components are manufactured in groups and not in a continuous flow. In medium-quantity production the production rate of equipment is greater than the demand rate for any single product type. Thus employing batch production the same equipment could be shared among multiple products.

Which of the following industries are classified as secondary industries? (a) beverages (b) financial services, (c) fishing, (d) mining, (e) power utilities, (f) publishing (g) transportation

Beverages, publishing, power utilities

In sand casting, the volumetric size of the pattern is (a) bigger than, (b) same size as, or (c) smaller than the cast part?

Bigger than

17.8 What is isothermal forming

Both the work and the forming tool are heated to the hot working temperature of the work

17.1 What are the differences between bulk deformation processes and sheet metal processes?

Bulk- causes workpiece to deform plastically, pushed to fill die sheet metal is on workpiece of sheets or strips, pushed into a die

In plaster mold casting, the mold is made of which one of the following materials: (a) Al2O3, (b) CaSO4-H2O, (c) SiC, or (d) SiO2?

CaSO_4-H_2O

Products purchased by companies to produce products or provide services are called which one of the following: (a) assembled products, (b) capital goods, (c) consumer goods, (d) final products, or (e) manufactured products?

Capital goods

2. What is a capital good? Provide an example.

Capital goods are those purchased by companies to produce goods and/or provide services. Example of a capital goods is a computer.

Cupolas are furnaces used to melt which of the following metals: (a) aluminum, (b) cast iron, (c) steel, or (d) zinc?

Cast iron

an iron-carbon alloy containing from 2.1% to about 4% or 5% carbon

Cast iron

Solidification shrinkage occurs in all metals with the exception of which one of the following?

Cast iron with high carbon content.

Ferrous metals include which of the following: (a) aluminum, (b) cast iron, (c) copper, (d) gold, and, (e) steel?

Cast iron, steel

Which of the following processes start with a material that is in a fluid or semi fluid state and solidifies the material in a cavity: (a) casting, (b) forging, (c) machining, (d) molding, (e) pressing, and, (f) turning?

Casting (for molten metal), molding (for hot polymer)

Casting process in which the mold is a thin shell of sand bonded by a thermosetting resin.

17.10 Why is friction generally undesirable in metal forming operations?

Causes high residual stress, causes cracks, increased power required, tool wear

What is unique about the polymer cellulose?

Cellulose is a polymer that grows in nature. Wood fiber contains about 50% cellulose and cotton fiber is about 95% cellulose.

An inorganic compound consisting of a metal (or semi-metal) and one or more nonmetals

Ceramic

Which one of the following engineering materials is defined as a compound containing metallic and nonmetallic elements: (a) ceramic, (b) composite, (c) metal, or, (d) polymer?

Ceramic

What is a chaplet?

Chaplets are metal supports of various designs used to hold the core in place in the sand mold.

According to the die casting video, what materials are most common for die-casting dies?

Common materials for die casting dies are hot-work tool steels, mold steels, maraging steels, and refractory metals such as tungsten alloys or molybdenum alloys.

A materials system composed of two or more distinct phases whose combination produces aggregate properties different from those of its constituents

Composite Material

Which of the following are the three basic types of static stresses to which a material can be subjected: (a) compression, (b) hardness, (c) reduction in area, (d) shear, (e) tensile, (f) true stress, and (f) yield?

Compression, tensile, shear

Consumer vs. capital good (Give Ex.'s)

Consumer goods - purchased directly by customers (Ex. car, TV, tennis racket) Capital goods - purchased by companies to produce goods/provide services (Ex. aircraft, computer, trucks and buses)

What type of atomic bonding characterizes the ceramics?

Covalent and ionic bonding

What is cross-linking in a polymer, and what is its significance?

Cross-linking is the formation of connections between the long-chain molecules in a polymer. It causes the polymer structure to be permanently altered. If the amount of cross-linking is low, the polymer is transformed into an elastomer; if cross-linking is significant, the polymer is transformed into a thermoset.

What is a machine tool?

Cutting tool operated by power - driven machines

5. What is a "datum feature"?

Datum feature is the actual configuration of the surface of the part.

What is a "datum feature"?

Datum feature is the actual configuration of the surface of the part.

Define the term "datum".

Datum is a theoretically exact entity such as point, line, plane, or axis of a configuration. It is used as a reference for other features of a part or assembly

individual parts, such as nails, gears, bearing balls, cans, engine blocks

Discrete Products

What is the most common fiber material in fiber-reinforced plastics?

E-glass.

Which one of the following types of stress strain relationship best describes the behavior of metals at temperatures above their respective recrystallization points: (a) elastic and perfectly plastic, (b) elastic and strain hardening, (c) perfectly elastic, or (d) none of the above?

Elastic and perfectly plastic

Which one of the following types of stress strain relationship best describes the behavior of most metals at room temperature: (a) elastic and perfectly plastic, (b) elastic and strain hardening, (c) perfectly elastic, or (d) none of the above?

Elastic and strain hardening

Elastomers and thermosetting polymers are both cross-linked. Why are their properties so different?

Elastomers are lightly cross-linked, whereas thermosets are highly cross-linked. Light cross-linking allows extensibility; a highly cross-linked structure makes the polymer rigid.

If engineering strain and true strain were measured simultaneously during a tensile test, which would have the higher value: (a) engineering strain or (b) true strain?

Engineering strain

Properties of Aluminum

Excellent corrosion resistance, very ductile metal, competitive with steels when heat treated

Name the two basic categories of casting processes.

Expendable mold process and Permanent mold process

Name the two basic categories of casting processes.

Expendable-mold, permanent-mold

Name some of the important applications of FRPs.

FRPs are used in modern aircraft as skin parts, automobile body panels, printed circuit boards, tennis rackets, boat hulls, and a variety of other items.

Name & define 2 categories of overhead costs in a manufacturing company

Factory - running operations Corporate - indirectly related operations

Metals that arealloys of iron and carbon; includes steel and cast iron

Ferrous

17.5 Indicate the mathematical equation for the flow curve

Flow stress = Strength strain ^ strain hardening exponent

The spiral mold test is a test for which one of the following properties of the casting metal?

Fluidity.

What are some of the general defects encountered in casting processes? Name and briefly describe three.

General defects include: (1) misruns, in which the casting solidifies before filling the mold cavity; (2) cold shuts, in which two portions of metal flow together but there is lack of fusion at the joint; (3) cold shots, where solid globules of cast metal become entrapped in the casting; (4) shrinkage cavity, which is a depression on the casting surface or an internal void in the casting caused by solidification shrinkage; (5) microporosity, which is a network of small voids throughout the casting caused by localized solidification shrinkage; and (6) hot tearing, which is a crack in the casting caused by a mold that does not yield to the metal during the early stages of solidification shrinkage.

o Design for robustness

Generating parts that can counteract the effect of variation

an inorganic, nonmetallic material that cools to a rigid solid without crystallization.

Glass

What is glazing, as applied to ceramics?

Glazing involves the application of a surface coating of oxides such as alumina and silica, usually to a porous ceramic product such as earthenware, to make the product more impervious to moisture and more attractive.

o Concurrent design

Goal: increase quality & reliability Includes suppliers as part of design

Which of the following operations are classified as material removal processes (a) anodizing, (b) brazing, (c) forging, (d) grinding, (e) milling, (f) sintering, and (g) turning?

Grinding, milling, turnging

What does heat of fusion mean in casting?

Heat of fusion is the amout of heat energy required to transform the metal from solid state to liquid state

Low carbon steels have a _________ strength, hardness, hot hardness, wear resistance, and toughness than plain carbon steels

Higher

Which die-casting machines usually have a higher production rate, cold-chamber or hot-chamber, and why?

Hot-chambe because for cold-chamber you need to ladle the liquid metal into the chamber from an external source.

Which die-casting machines usually have a higher production rate, cold-chamber or hot-chamber, and why?

Hot-chamber machines are faster because cold-chamber die casting machines require molten metal to be ladled into the chamber from an external source. Ladling takes more time than injecting the molten metal into the die as in the hot-chamber operation.

What are some of the principal applications of cemented carbides, such as WC-Co?

Important applications of WC-Co include cutting tool inserts, drawing dies, rock drilling bits, dies for powder metallurgy, and other applications where hardness is a critical factor.

What are the 3 groups of superalloys?

Iron, Nickel, and Cobalt based alloys

One of the first applications of digital computers in manufacturing was direct numerical control, which is best described by which one of the following: (a) computers used to count work units on a production line, (b) flexible manufacturing, (c) mainframe computers used to remotely control machine tools in a factory, (d) personal computers used to schedule production, or (e) shop floor control?

Mainframe computers used to remotely control machine tools in a factory

The process of converting raw materials into functional products

Manufacturing

4. Define manufacturing capability.

Manufacturing capability refers to the technical and physical feasibility limitations of a manufacturing firm and each of its plants.

Name two manufacturing support departments

Manufacturing engineering Production planning & control

10. Name two departments that are typically classified as manufacturing support departments.

Manufacturing engineering (ii) Production planning and control

Name the three basic categories of composite materials.

Metal matrix composites (MMCs), ceramic matrix composites (CMCs), and polymer matrix composites (PMCs).

What is a chaplet?

Metal supports that hold the position of the core.

4 categories of engineering materials used in manufacturing?

Metals Ceramics Polymers ___ Composites

Define batch production & describe why it is often used for medium-quantity production products

Method to manufacture a production small batches at one time to reduce costs Why? So too much change doesn't occur

In addition to fillers and plasticizers, what are some other additives used with polymers?

Other additives include (1) lubricants - to reduce friction and improve flow; (2) flame retardents; (3) colorants; (4) cross-linking agents, (5) antioxidants, and (6) ultraviolet light absorbers.

What are the four most common elements in the earth's crust?

Oxygen, silicon, aluminum, and iron

How are product variety and production quantity related when company typical factories?

Relation between product variety and production quantity is inversely proportional Increase in product variety leads to decrease in production quantity

Hardness is best defined as which one of the following: (a) energy absorbed by a material when an object strikes its surface, (b) resistance to bending, (c) resistance to permanent indentation, or (d) resistance to scratching?

Resistance to permanent indentation

resolution

Resolution is the smallest difference in dimensions that the instrument can detect.

The term vulcanization is associated with which one of the following: (a) adhesives, (b) bronze, (c) fire, (d) rubber, or (e) wood?

Rubber Vulcanization or vulcanisation is a chemical process for converting natural rubber or related polymers into more durable materials by the addition of sulfur or other equivalent curatives or accelerators.

Which casting process is the most important commercially?

Sand casting

Which one of the following casting processes is the most widely used: (a) centrifugal casting, (b) die casting, (c) investment casting, (d) sand casting, or (e) shell casting?

Sand casting

What are the advantages and disadvantages of sand casting over investment casting?

Sand casting provides low production cost for a wide variety of metals, shapes and sizes. The size of the casting is unlimited. The disadvantage is the surface finish and dimensional control are not very good.

6. How does a shaping process differ from a surface processing operation?

Shaping process changes the shape of the material by various methods whereas surface processing operations are performed to clean, treat, coat or deposit material onto exterior surface of the work material.

Silica sand has which one of the following compositions: (a) Al2O3, (b) SiO, (c) SiO_2, or (d) SiSO_4?

SiO_2

What are the elements in the ceramic material Sialon?

Sialon consists of the elements silicon, aluminum, oxygen, and nitrogen.

Inventions of the Industrial Revolution include which one of the following: (a) automobile, (b) cannon, (c) printing press, (d) steam engine, or, (e) sword?

Steam engine

an iron-carbon alloy containing from 0.02% to 2.1% carbon

Steel

What do the digits in the AISI-SAE designation scheme represent? (for example YYXX)

The first 2 numbers designate the type of steel (10=plain carbon steel) and the second 2 numbers designate the % carbon it contains.

What is meant by the term interface in the context of composite materials?

The interface is the boundary between the component phases in a composite material.

Difference btw. thermoplastic and thermosetting polymer?

Thermoplastic - deform while heating, soft/weak, can remold, linear chain polymers (Ex. mugs, bags, and toys) Thermosetting - do not deform while heating, hard/brittle, can't remold, 3D structure (Ex. electrical things, telephone parts)

How do the properties of thermosetting polymers differ from those of thermoplastics?

Thermosets are more rigid, brittle, capable of higher service temperatures, and cannot be remelted.

What do bauxite and corundum have in common?

They are both minerals of alumina.

What is the Antioch process?

This process involves mixing about 50% sand with plaster, heating the mold in an autoclave (an oven that uses superheated steam under pressure), and then drying. EXTRA -> greater permeability than a conventional plaster mold.

What are the general physical properties of ceramic materials?

Typical physical properties include electrical and thermal insulating, medium density (mostly below the density of metals), high melting temperatures, and thermal expansion usually less than metals.

Identify some of the characteristic properties of composite materials

Typical properties include (1) high strength-to-weight and stiffness-to-weight ratios; (2) good fatigue properties and toughness; (3) anisotropic properties in many cases; and (4) other properties and features that are difficult or impossible to obtain with metals, ceramics, or polymers alone.

o Design for environment

Using materials and processes that are environmentally friendly

What is the difference between vacuum permanent-mold casting and vacuum molding?

Vacuum permanent mold casting is a type of low pressure casting that uses vacuum to pour molten metal inside the mold cavity. Vacuum molding is a method of sand casting that uses vacuum pressure in place of chemical binder to hold the sand mold together

What is the difference between vacuum permanent-mold casting and vacuum molding?

Vacuum permanent-mold casting is a form of low-pressure casting in which a vacuum is used to draw molten metal into the cavity. Vacuum molding is sand casting in which the sand mold is held together by vacuum pressure rather than by a chemical binder.

What are some of the weaknesses of ceramics that might be corrected in fiber-reinforced ceramic matrix composites?

Weaknesses of ceramics include low tensile strength, poor toughness, and susceptibility to thermal cracking.

What are the most common metals used in die casting?

Zinc, magnesium, tin, copper, aluminum

any homogeneous mass of material, such as a metal in which the grains all have the same crystal lattice structure

a phase

Flatness

a surface having all elements in one plane. A flatness tolerance specifies a tolerance zone defined by two parallel planes within which the surface must lie

Cylindricity

a surface of revolution in which all points of the surface are equidistant from a common axis. A cylindricity tolerance specifies a tolerance zone bounded by two concentric cylinders within which the surface must lie

Circularity

a surface of revolution where all points at the surface intersected by any plane perpendicular to an axis are equidistant from that axis. In the case of a sphere all points at the surface intersected by any plane passing through a common center are equidistant from that center

Angularity

a surface or center plane or axis at a specified angle (other than 90 degree) from a datum plane or axis

Parallelism

a surface or center plane, equidistant at all points from a datum plane or an axis, equidistant along its length from one or more datum planes or a datum axis

List some applications of low carbon steels (< 0.20% C)

automobile sheetmetal parts, plate steel for fabrication, railroad rails

2.000 +0.005, -0.000

basic size=2.000 with a unilateral tolerance of 0.005 on the upper side. hence, the lower limit=2.000 and the upper=2.005

2.005: +0.000, -0.005

basic size=2.005 with a unilateral tolerance of 0.005 on the lower side. hence the lower limit=2.000 and the upper=2.005

Which one of the following casting metals is most important commercially: (a) aluminum and its alloys, (b) bronze, (c) cast iron, (d) cast steel, or (e) zinc alloys?

cast iron

Which of the following are referred to as thin film deposition processes (two correct answers): (a) chemical vapor deposition, (b) electroplating, (c) extrusion, (d) painting, and (e) physical vapor deposition?

chemical vapor deposition, physical vapor deposition EXTRA-> Coating: electroplating, painting, anodizing

Stainless steels' principal alloying element is ___________, usually greater than 15% (to protect surface from corrosion)

chromium (or sometimes Nickel)

nominal size

designation used for general identification of size

Which of the following cost categories are considered to be variable costs rather than fixed costs (two correct answers): (a) direct labor, (b) equipment, (c) insurance, (d) maintenance, (e) work material, and (f) research and development?

direct labor, work material

Hooke's Law defines which one of the following regions of the stress strain relationship for engineering materials: (a) elastic region, (b) plastic region, or (c) neither?

elastic region

The volume of the riser must always be greater than the volume of the casting in order to avoid premature solidification of the riser.

ceramics based primarily on silica and distinguished by their noncrystalline structure

glasses

17.7 Indicate some of the advantages of cold working relative to warm and hot working

greater accuracy, better surface finish, high strength and hardness, different properties in different directions, cost efficient

Which of the following are advantages of die casting over sand casting (four best answers): (a) better surface finish, (b) closer tolerances, (c) higher melting temperature metals can be cast, (d) higher production rates, (e) larger parts can be cast, and (f) mold can be reused?

higher production rates, closer tolerances, better surface finish, mold can be reused

2.005 | 2.000

implies that the acceptable range is from 2.000 to 2.005 limits. since, the largest limit is place at the top, this implies an external dimension

What is flash in die casting?

liquid metal under high pressure squeezes into the small space between the die halves at the parting line or into the clearances around the cores and ejector pins.

Investment casting is also known by which one of the following names: (a) fast-payback molding, (b) full-mold process, (c) lost-foam process, (d) lost-pattern process, or (e) lost-wax process?

lost-wax process

List some applications of medium carbon steels (0.20% ~ 0.50% C)

machinery components and engine parts such as crankshafts and connecting rods

Which of the following features and terms are associated with batch production: (a) cellular manufacturing, (b) mass production, (c) medium quantity production, (d) production equipment is dedicated to one product, and (e) setup time between batches is a disadvantage?

medium quantity production, setup time between batches is a disadvantage

metal solidifies before filling the cavity

allowance

minimum clearance b/n the maximum material conditions(MMC) of mating parts. Allowance=MMC of hole-MMC of shaft

For which one of the following reasons is a green mold named: (a) green is the color of the mold, (b) moisture is contained in the mold, (c) the mold is cured, or (d) the mold is dry?

moisture is contained in the mold

unilateral tolerances

one-sided variation from the basic size

refers to the use of outside contractors to perform work that was traditionally accomplished inhouse

outsourcing

tolerances of orientation

parallelism, angularity, perpendiculity

Which of the following names are applied to a process in which a molten metal is poured into a heated lower die, and the upper die is closed to create the mold cavity only after solidification begins: (a) liquid-metal casting, (b) liquid-metal forging, (c) rheocasting, (d) squeeze casting, or (e) thixocasting?

squeeze casting, liquid-metal forging

17.11 What is sticking friction in metalworking?

sticking causes the work to stick to the tool instead of sliding

tolerances of form

straightness, roundness, flatness, cylindricity

In addition to corrosion resistance, stainless steels are noted for their combination of __________ and __________

strength; ductility

basic shaft system

system where the maximum shaft is taken as the basic size. an allowance for each mating part is then assigned and tolerances are applied on both sides of and away from this allowance

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