Material Process Exam 2
Which of the following is typical of the starting work geometry in sheet metal processes: (a) highvolume-to-area ratio or (b) low volume-to-area ratio?
Answer. (b).
Which one of the following abrasive materials is most appropriate for grinding steel and cast iron
(a) aluminum oxide
Which of the following will improve surface finish in grinding
(a) denser wheel structure, (b) higher wheel speed (g) lower workspeed
Of the following abrasive materials, which one has the highest hardness
(b)cubic boron nitride
Which one of the following conventional machining processes is closest to grinding
(b)milling
Smaller grain size in a grinding wheel tends to
(c) improve surface finish
Which one of the following abrasive materials is most appropriate for grinding nonferrous metals
(d) silicon carbide
Which one of the following abrasive processes achieves the best surface finish
(d) superfinishing
23.1 Which of the following are the usual objectives of heat treatment (three best answers): (a) increase hardness, (b) increase melting temperature, (c) increase recrystallization temperature, (d) reduce brittleness, (e) reduce density, and (f) relieve stresses?
- increase hardness - reduce brittleness - relieve stresses
23.3 Which of the following are typical reasons to anneal a metal (three correct answers): (a) to heat the metal for hot working, (b) to increase strength and hardness, (c) to recrystallize strain-hardened metals, (d) to reduce brittleness, (e) to reduce ductility, and (f) to relieve stresses?
- reduce brittleness - to recrystallize strain -hardened metals - relieve stressesEXTRA - soften metals for improved machinability or formability - alter microstructure to obtain desirable mechanical properties
Powder Metallurgy- Outline
1. The Characterization of Engineering Powders2. Production of Metallic Powders3. Conventional Pressing and Sintering4. Alternative Pressing and Sintering Techniques5. Materials and Products for PM6. Design Considerations in Powder Metallurgy
Basic components of NC System
A part program of instruction Machine Control Unit Processing Equipment
Hot working of metals refers to which one of the following temperature regions relative to themelting point of the given metal on an absolute temperature scale: (a) room temperature, (b) 0.2Tm,(c) 0.4Tm, or (d) 0.6Tm?
Answer. (d).
23.12 The most common method for measuring hardenability is which one of the following: (a) Brinell hardness test, (b) Jominy end-quench test, (c) Rockwell hardness test, or (d) tensile test?
Jominy end-quench test
Most sheet metalworking operations are performed as which one of the following
cold working
The starting workpiece in steel hot rolling of plate and sheet stock is which of the following
slab
23.9 The treatment in which the brittleness of martensite is reduced is called which one of the following: (a) aging, (b) annealing, (c) austenitizing, (d) normalizing, (e) quenching, or (f) tempering?
tempering
23.11 Hardenability refers to the relative capacity of a steel to be hardened by transformation to martensite: (a) true or (b) false?
true
Which of the following will help to reduce the incidence of heat damage to the work surface ingrinding
(a) frequent dressing or truing of the wheel, (d) higher workspeeds, (e) lower infeeds, and (g)lower workspeeds
Which one of the following abrasive materials is most appropriate for grinding hardened tool steel
(b) cubic boron nitride
The term deep grinding refers to which one of the following
(b) external cylindrical creep feed grinding
Which of the following are advantages and characteristics of hot working relative to cold working(four correct answers): (a) fracture of workpart is less likely, (b) friction is reduced, (c) increasedstrength properties, (d) isotropic mechanical properties, (e) less overall energy is required, (f) lowerdeformation forces is required, (g) more significant shape changes are possible, and (h) strain-ratesensitivity is reduced?
Answer. (a), (d), (f), and (g).
The flow curve expresses the behavior of a metal in which of the following regions of thestress-strain curve: (a) elastic region or (b) plastic region?
Answer. (b)
The coefficient of friction between the part and the tool in cold working tends to be (a) higher, (b)lower, or (c) no different relative to its value in hot working?
Answer. (b).
21.8 A live center is one way of holding a workpiece in the headstock of a lathe, whereas a dead center is used to hold the work in the tailstock: (a) true or (b) false?
Answer. (b). Both live centers and dead centers are used in the tailstock. The live center rotates with the work whereas the dead center does not rotate.
Which of the following are bulk deformation processes (three correct answers): (a) bending, (b) deepdrawing, (c) extrusion, (d) forging, (e) rolling, and (f) shearing?
Answer. (c), (d), and (e).
Increasing strain rate tends to have which one of the following effects on flow stress during hotforming of metal: (a) decreases flow stress, (b) has no effect, or (c) increases flow stress?
Answer. (c).
The average flow stress is the flow stress multiplied by which of the following factors: (a) n, (b)(1+n), (c) 1/n, or (d) 1/(1+n), where n is the strain-hardening exponent?
Answer. (d).
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?
a
Powder Metallurgy (PM)
Metal processing technology in which parts are produced from metallic powdersUsual PM production sequence:1. Pressing - powders are compressed into desired shape to produce *green compact~ Accomplished in press using punch-and-die2. Sintering - green compacts are heated to bond the particles into a hard, rigid mass~ Temperatures are below melting point
23.2 Annealing consists of heating a metal to a suitable temperature, holding at that temperature for a certain time, and then slowly cooling: (a) true or (b) false?
True
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?
a
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?
a
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?
a
10.3 Sand casting is which of the following types of casting process: (a) expendable mold or (b) permanent mold?
a
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?
a
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?
a
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?
a
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?
a
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
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
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?
a
21.11 Most vertical boring machines are equipped for both turning and boring and are used for large, heavy work parts with large diameters: (a) true or (b) false?
a
21.12 The twist drill is the most common type of drill bit: (a) true or (b) false?
a
21.6 Boring and reaming share the common feature that they are both used to enlarge an existing hole: (a) true or (b) false?
a
21.7 Knurling is performed on a lathe, but it is not a metal cutting operation: (a) true or (b) false?
a
21.9 Which one of the following cutting tools cannot be used on a turret lathe: (a) broach, (b) cutoff tool, (c) drill bit, (d) single-point turning tool, or (e) threading tool?
a
MC 16.3As particle size increases, inter-particle frictiona) increasesb) decreasesc) stays the same
a
MC 16.6Repressing refers to a pressworking operation used to compress a sintered part in a closed die to achieve closer sizing and better surface finisha) trueb) false
a
MC 16.8In cold isostatic pressing the mold is most typically made of which of the following?a) rubberb) sheet metalc) textiled) thermosetting polymere) tool steel
a
21.19 A vertical milling machine is more appropriate than a horizontal milling machine for performing which of the following types of operations (three best answers): (a) end milling, (b) face milling, (c) peripheral milling, (d) plain milling, (e) slab milling, and (f) surface contouring?
a b and f
21.4 A lathe can be used to perform which of the following machining operations (three correct answers): (a) boring, (b) broaching, (c) drilling, (d) milling, (e) planing, and (f) turning?
a c and f
23.7 Martensite can best be defined as which one of the following: (a) a mixture of ferrite and carbide phases obtained by rapid cooling of austenite, (b) a mixture of ferrite and carbide phases obtained by slow cooling of austenite, (c) a phase consisting of an iron-carbon solution whose composition is the same as the austenite from which it was derived, or (d) a solution of cementite in ferrite obtained by rapid cooling of austenite?
a solution of cementite in ferrite obtained by rapid cooling of austenite
Which of the following would tend to give higher material removal rates
a) larger grain size
MC 16.10Which of the following design features would be difficult or impossible to achieve by conventional pressing and sintering? (3)a) outside rounded cornersb) side holesc) threaded holesd) vertical-stepped holese) vertical wall thickness of 1/8 in
a, b, c
MC 16.9Which of the following processes combines pressing and sintering of the metal powders? (3)a) hot isostatic pressingb) hot pressingc) metal injection moldingd) pressing and sinteringe) spark sintering
a, b, e
MC 16.5Which of the following statements is correct in the context of metallic powders? (3)a) porosity+packing factor=1b) packing factor=1/porosityc) packing factor=1-porosityd) packing factor=-porositye) packing factor=(bulk density)/(true density)
a, c, e
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,b,d
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?
a,b,d,f
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?
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?
a,c
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?
a,d,f
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
a,e
5. Manual method of workpart transfer are probably closest by which of the following mechanizedMethod of transfer?a. Asynchronous b. Continuous c. Synchronous
a. Asynchronous
7. Which of the following automation system will be best suited to high production quantities.and high production ratesa. Fixed b. Programmable c. Flexible
a. Fixed
8. Lean production means doing more with less, and doing it bettera. True b. False
a. True
23.13 In precipitation hardening, the hardening and strengthening of the metal occurs in which one of the following steps: (a) aging, (b) quenching, or (c) solution treatment?
aging
Which of the following stress or strength parameters is used in the computation of rolling force
average flow stress
Which of the following stress or strength parameters is used in the computation of the force in an extrusion operation
average flow stress
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?
b
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?
b
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?
b
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?
b
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?
b
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?
b
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?
b
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?
b
21.13 When the drill bit in a drilling operation exits the opposite side of the work, the resulting hole is called which one of the following: (a) a blind hole or (b) a through hole?
b
21.20 The basic milling machine is which one of the following: (a) bed type, (b) knee and column, (c) profiling mill, (d) ram mill, or (e) universal milling machine?
b
21.23 A broaching operation is best described by which one of the following: (a) a rotating tool moves past a stationary workpart, (b) a tool with multiple teeth moves linearly past a stationary workpart, (c) a workpart is fed past a rotating cutting tool, or (d) a workpart moves linearly past a stationary single-point tool?
b
21.25 Which one of the following terms is used for cutting external threads using self-opening threading dies: (a) tapping, (b) thread chasing, (c) thread forming, or (d) thread milling?
b
21.26 Gear hobbing is a special form of which one of the following machining operations: (a) grinding, (b) milling, (c) planing, (d) shaping, or (e) turning?
b
21.3 In a turning operation, the change in diameter of the workpart is equal to which one of the following: (a) 1 x depth of cut, (b) 2 x depth of cut, (c) 1 x feed, or (d) 2 x feed?
b
21.5 A facing operation is normally performed on which one of the following machine tools: (a) drill press, (b) lathe, (c) milling machine, (d) planer, or (e) shaper?
b
MC 16.22Which of the following most closely typifies the sintering temperatures in PM?a) 0.5 Tmb) 0.8 Tmc) Tm (Tm=melting temp of material)
b
21.21 Typical operations performed on a machining center include which of the following (two best answers): (a) boring, (b) drilling, (c) milling, (d) sawing, and (e) turning?
b and c
MC 16.2For a given weight of metallic powders the total surface area of the powder is increased by which of the following? (2)a) larger particle sizeb) smaller particle sizec) higher shape factord) smaller shape factor
b and c
21.2 Which of the following are examples of generating the workpart geometry in machining, as opposed to forming the geometry (two best answers): (a) broaching, (b) contour turning, (c) drilling, (d) profile milling, and (e) thread cutting?
b and d
21.24 The three basic types of sawing, according to type of blade motion involved, are which of the following: (a) abrasive cutoff, (b) bandsawing, (c) circular sawing, (d) contouring, (e) friction sawing, (f) hacksawing, and (g) slotting?
b c and f
21.15 Reaming is used for which of the following functions (three correct answers): (a) accurately locate a hole position, (b) create a stepped hole, (c) enlarge a drilled hole, (d) improve surface finish on a hole, (e) improve tolerance on hole diameter, and (f) provide an internal thread?
b d and e
21.17 Which of the following are classified as peripheral milling rather than face milling (three best answers): (a) end milling, (b) plain milling, (c) pocket milling, (d) slab milling, (e) straddle milling, and (f) surface contouring?
b d and e
MC 16.7Impregnation refers to which of the following? (2)a) filling the pores of the PM part with a molten metalb) putting polymers into the pores of a PM partc) soaking oil by capillary action into the pores of a PM partd) something that should not happen in a factory
b, c
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?
b,d
MC 16.1The particle size that can pass through a screen is obtained by taking the reciprocal of the mesh count of the screen.a) trueb) false
b. The given description neglects consideration of the screen wire thickness
Which of the following are alternative names for indirect extrusion (two correct answers)
backward extrusion, reverse extrusion
23.8 Of the following quenching media, which one produces the most rapid cooling rate: (a) air, (b) brine, (c) oil, or (d) pure water?
brine
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.?
c
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?
c
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?
c
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?
c
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?
c
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?
c
11.3 Silica sand has which one of the following compositions: (a) Al2O3, (b) SiO, (c) SiO2, or (d) SiSO4?
c
21.10 Which one of the following turning machines permits very long bar stock to be used: (a) chucking machine, (b) engine lathe, (c) screw machine, (d) speed lathe, or (e) turret lathe?
c
21.1 Machined parts can be classified as rotational or nonrotational. Which of the following are examples of operations that create nonrotational geometries (two best answers): (a) boring, (b) drilling, (c) milling, (d) planing, and (e) turning?
c and 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?
c,d
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?
c,d,e
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?
c,e,f,h
9. Closed-loop (feedback) control system -a. Is a system in which the output variable is compared with an input parameter, and any difference between the two is used to drive the output into agreement with the inputb. Risk that the actuator will not have the intended effectc. Both of the above are true d. None of the above is true
c. Both of the above are true
1. The standard coordinate system for numerical control machine tools is based on which of the following:a. Cylindrical coordinates b. Polar coordinates c. Cartesian coordinates
c. Cartesian coordinates
4. Batch model lines are suited for which one of the following production situation?a. Job shop b. Mass production c. Medium production
c. Medium production
2. Identify which of the following is(are) point-to-point and not continuous path operation(s):a. Arc welding b. Drilling c. Spot welding d. b & ce. All of above
c. Spot welding
23.14 Which one of the following surface-hardening treatments is the most common: (a) boronizing, (b) carbonitriding, (c) carburizing, (d) chromizing, or (e) nitriding?
carburizing
The maximum possible draft in a rolling operation depends on which of the following parameters (two correct answers)
coefficient of friction between roll and work, roll diameter
Which of the following operations are closely related to open-die forging (three best answers)
cogging, fullering, upsetting
Which of the following are classified as forging operations (four correct answers)
coining, fullering, swagging, upsetting
Sheet-metal bending involves which of the following stresses and strains (two correct answers)
compressive, tensile
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?
d
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
d
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?
d
21.14 A tap is a cutting tool used to create which one of the following geometries: (a) external threads, (b) flat planar surfaces, (c) holes used in beer kegs, (d) internal threads, or (e) square holes?
d
21.22 A planing operation is best described by which one of the following: (a) a single-point tool moves linearly past a stationary workpart, (b) a tool with multiple teeth moves linearly past a stationary workpart, (c) a workpart is fed linearly past a rotating cutting tool, or (d) a workpart moves linearly past a single-point tool?
d
MC 16.4Which of the following powder shapes would have the lowest inter-particle friction?a) acicularb) cubicc) flakyd) sphericale) rounded
d
10. Open loops control system is used when the following condition(s):a. Actions performed by the control system are simple.b. Actuating function is very reliablec. Any reaction forces opposing the actuation are small enough as to have no effect on the actuationd. All of the above e. b & c only
d. All of the above
12. Safety monitoring systems possible responses to hazards:a. Sounding an alarm.b. Complete stoppage of the systemc. Taking corrective action to recover from the safety violationd. All of the above e. Only a & b
d. All of the above
13. Error recovery - possible strategies:a. Make adjustments at end of work cycleb. Stop the process to invoke corrective actionc. Make adjustments during current work cycled. All of the above e. Only b & c
d. All of the above
14. Device level of automation include:a. Actuators b. Sensorsc. Other hardware components to form individual control loops for the next leveld. All of the above e. Only a & b
d. All of the above
6. Automation in Production Systems includes:a. Automation of manufacturing systems in the factoryb. Computerization of the manufacturing support systemsc. The two categories overlap because manufacturing support systems are connected to the factory manufacturing systemsd. All of the above are true e. a & b only are true
d. All of the above
11. In Safety Monitoringa. Sensors are used to track the system's operation and identify conditions that are unsafe or potentially unsafeb. The reason for safety monitoring is to protect workersc. The reason for safety monitoring is to protect equipmentd. All of the above are true e. a & c only
d. All of the above are true
A circular sheet-metal slug produced in a hole punching operation will have the same diameter as the
die opening
In which of the following extrusion operations is friction a factor in determining the extrusion force
direct extrusion
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?
e
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?
e
3. Which of the following are characteristics of work situations that tend to promote the substitution of a robot in place of a human worker?a. frequent job change over b. Hazardous work c. Repetitive work cycle.d. all of the above e. b & c only
e. b & c only
Springback in a sheet-metal-bending operation is the result of which one of the following
elastic recovery of the metal
Which of the following processes are classified as high-energy-rate forming processes (two best answers)
electromagnetic forming, explosive forming
Johnson's formula is associated with which one of the four bulk deformation processes
extrusion
Production of pipes and tubes is associated with which of the following bulk deformation processes (three correct answers)
extrusion, roll piercing, tube sinking
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?
f
21.16 The distinguishing feature between a drilling fixture and a drill jig is that the fixture provides a means of guiding the tool during the hole-making operation: (a) true or (b) false?
false
21.18 The difference between up milling and down milling is that in down milling the direction of motion of the cutter teeth is opposite the feed direction when the teeth cut into the work: (a) true or (b) false?
false
Flash in impression die forging serves no useful purpose and is undesirable because it must be trimmed from the part after forming
false
The production of tubing is possible in indirect extrusion but not in direct extrusion
false
Which of the following stress or strength parameters is used in the computation of the maximum force in a forging operation
final flow stress
Which of the following are variations of sheet-metal-bending operations (two best answers)
flanging, hemming
23.10 Tempering is a heat treatment applied to hardened steels that is best defined as which of the following (one correct answer): (a) heating and soaking at a temperature above the austenitizing level followed by rapid cooling, (b) heating and soaking at a temperature above the austenitizing level followed by slow cooling, (c) heating and soaking at a temperature below the austenitizing level followed by rapid cooling, or (d) heating and soaking at a temperature below the austenitizing level followed by slow cooling,?
heating and soaking at a temperature above the austenitizing level followed by rapid cooling
As sheet-metal stock hardness increases in a blanking operation, the clearance between punch and die should be
increased
23.6 The time-temperature-transformation curve (TTT curve) for steel can best be described by which one of the following: (a) indicates how annealing is used to achieve a given desired microstructure, (b) indicates how cooling rate affects the transformation of austenite into various possible phases, (c) indicates how martensite is gradually transformed into tempered martensite as a function of time, or (d) indicates how various phases are obtained during heating as a function of time and temperature?
indicates how cooling rate affects the transformation of austenite into various possible phases
Which of the following descriptions applies to a V-bending operation as compared to an edge- bending operation (two best answers)
inexpensive tooling, used for low production
Which one of the following is the best definition of bend allowance
length before bending of the straight sheet-metal section to be bent
The cutting force in a sheet-metal blanking operation depends on which mechanical property of the metal
modulus of elasticity
Which one of the following press types is usually associated with the highest production rates in sheet-metal-stamping operations
open back inclinable
23.4 When annealing is performed to allow for further cold working of the part, it is called which one of the following: (a) full anneal, (b) normalizing, (c) process anneal, or (d) recovery anneal?
process anneal
Which one of the following stamping dies is the most complicated
progressive die
In a sheet-metal-cutting operation used to produce a flat part with a hole in the center, the part itself is called a blank, and the scrap piece that was cut out to make the hole is called a slug
true
23.5 The hardness of steel increases with increasing carbon content, but the increase is achieved only through heat treatment: (a) true or (b) false?
true*