MFGE 231

Two advantages of expendable molds are:

Complex part shapes, economy of scope,

Which one of the following materials has the highest hardness: 1)Alumina 2)Gray cast iron 3)Hardened tool steel 4)High carbon steel 5)Aluminum?

Alumina

All of the following are advantages of machining except: 1)Result in good dimensional accuracy and surface finish 2)Capable of producing external and internal threads 3)Capable of producing accurate holes and straight edges 4)Always quicker than alternative shaping processes 5)Capable of working with a wide range of materials

Always quicker than alternative shaping processes

What are the main two differences between basic permanent mold process and die casting?

Basic mold uses gravity and die casting uses pressure for mold filling and Basic mold needs a simple actuator to operate the mold, while die casting requires a full machine

When a tolerance is specified in both the positive and negative directions from the nominal dimension, what it is called?

Bilateral Tolerance

Examples of Ferrous Metals are what?

Cast iron, and steel

A Chip breaker is needed for cutting tools to break what kind of chip?

Continuous chip

All of the following are true about sheet metal V-bending except: 1)Performed on press brakes 2)Produces low production rate 3)Dies are complicated and expensive 4)Does not need pressure pad 5)Effect of the spring-back should be included in the punch angle

Dies are complicated and expensive

While complex shapes can be produced by casting, the use of cores and sharp corners should be avoided when possible. (T/F)?

TRUE

All the following processes can be performed on a lathe, except: 1)Drilling 2)Horizontal boring 3)Vertical boring 4)Threading 5)Chamfering 6)Facing

Vertical boring

All of the following are holding methods of parts on a lathe except: 1)Between centers 2)Face plate 3)Dependent three-jaw chuck 4)Independent four-jaw chuck 5)Vise and fixtures 6)Collet

Vise and fixtures

What processes can provide a permanent joint?

Welding, expansion fits, soldering, adhesive bonding

All of the following are advantages of hot working except: 1)Strength properties of product are generally isotropic 2)Can be used for metals that fracture in cold working 3)Part shape can be significantly modified 4)Lower mechanical forces and power than cold working are required 5)Higher dimensional accuracy than cold working

Higher dimensional accuracy than cold working (CTE..)

All of the following are advantages of using powder metallurgy except: 1)Production can be automated 2)produce net-shape or near net-shape parts 3)Homogeneous density throughout the part 4)very little material waste 5)Certain alloys can not be produced in any other way

Homogeneous density throughout the part

All of the following are advantages of thread rolling over thread cutting except: 1)Stronger threads 2)Better fatigue resistance 3)Better material utilization 4)No need for tooling 5)Higher production rate

No need for tooling

High-volume production of assembled products is most closely associated with what layout type?

A product layout

What value of process capability index (PCI) will result in a greater proportion of out-of-tolerance parts:

0.5 or lowest value possible

The solidification of alloys over a range of temperatures and a period of time has what two bad effects?

1)Different chemical compositions across castings 2)Different mechanical properties across casting

A riser needs to be designed to what? (three answers)

1)Freeze after main casting 2)be optimized to reduce waste after being removed from finished casting 3)promote directional solidification

If the product tolerance is set so that the process capability index (PCI) equals 1.0, then what will the percentage of parts that are within tolerance will be closest to?

100%

What manufacturing processes start with a material that is in a fluid or semifluid state and solidifies the material in a cavity?

Casting, Molding, Extrusion

In a GO/NO‑GO gage, what best describes the function of the GO gage?

Checks the maximum material condition

Which machine-tool has the following features: - Has turret in place of tailstock - Parts are held by a chuck not a collet - Manual loading and unloading - Automatic cutting operations 1)CNC turning center 2)Boring machine 3)Bar and screw machines 4)Chucking machine 5)Multiple-spindle bar machine

Chucking machine

Which one of the following materials has the highest modulus of elasticity: Al, Diamond, steel, Ti, Tungsten?

DIAMOND

Three of the following additive manufacturing technologies use moving spot scanning mode: 1)Sheet lamination 2)Direct Energy Deposition 3) 3D printing 4)Selective laser sintering 5)Mask projection stereolithography 6)Stereolithography 7)Multi-jet modeling (MJM)

Direct Energy Deposition, Selective laser sintering, and Stereolithography

Which type of chip does result from these conditions: - High tool friction - Low cutting speed - Bad surface finish - Machining brittle materials 1)Continuous chip 2)Continuous chip with built-up-edge 3)Discontinuous chip 4)Serrated chip

Discontinuous chip

Draft angles are promoted in expendable molds to aid in part removal from mold. (T/F)?

FALSE

For quality inspection, gaging provides more information than measurement: (T/F)?

FALSE

In comparing sampling inspection and 100% inspection using manual methods, only 100% inspection can guarantee 100% good quality. (T/F)?

FALSE (100% good quality cannot be guaranteed using 100% inspection by manual methods because of human error during the manual inspection procedure.)

A coordinate measuring machine (CMM) consists of a contact probe and a mechanism to position the probe in only two dimensions relative to the surfaces and features of a work part. (T/F)?

FALSE (CMMs position the probe in three dimensions, not two.)

To reduce the size of a part in a turning operation, cross-slide of the lathe should move into the part by the difference between outside diameter and targeted diameter. (T/F)?

FALSE (Cross-slide motion is the depth of cut which is half the difference between the outside diameter and the targeted diameter.)

To hold work in a drill press, a custom-designed fixture is needed to guide tool during drilling. (T/F)?

FALSE (Drill jigs not fixtures provide tool guidance.)

In vertical milling machine, machine head has specific speed values for the quill to choose from, and can also provide vertical power feed for the quill. A separate drive provides power feed to the table. (T/F)?

FALSE (Quill speeds are continuous.)

Turning is performed with a single point cutting tool and a rotating workpiece. However, drilling is performed with a twist drill, which is also a single-point tool but it is rotating, while workpiece doesn't rotate. (T/F)?

FALSE (a twist drill is a multiple cutting edge tool, specifically with two cutting edges)

In powder metallurgy, powder mixing is a combining process of powders of same chemistry and different particle sizes. (T/F)?

FALSE (combining different chemistries)

The starting blank for a cup is a concave part in a deep drawing process, in which the blank is held under a die cavity, while a punch pushes the metal into die opening. (T/F)?

FALSE (flat blank)

Wood patterns are a compromise between the easily shaped plastic patterns and the expensive but long lasting metal patterns. (T/F)?

FALSE (plastic is the compromise between wood and metal)

CNC machining is a subtraction process that can be used in additive manufacturing to produce parts layer by layer. (T/F)?

FALSE (subtraction manufacturing)

Forge press applies impact force in hot forging, while forge hammer applies gradual force in cold forging. (T/F)?

FALSE (forge hammer does this in hot forming)

Casted parts should be radially symmetrical in centrifuge casting. (T/F)?

FALSE (small parts)

Assembly is defined as a manufacturing operation in which two or more parts are permanently joined to form a new entity: (T/F)?

FALSE (not all assembly ops form permanent* joint)

Automated 100% inspection can be integrated with the manufacturing process to accomplish what?

Feedback of data to adjust process, sortation of good/bad parts

Three of the following are advantages of using additive manufacturing: 1)Finished product of multiple parts can be produced without further assembly 2)High production rate 3)No tooling such as molds or dies are needed 4)Existing parts can be copied without the need for a CAD model 5)Produced parts are always solid and heavy-weight 6)It is possible to produce complex 3D shapes

Finished product of multiple parts can be produced without further assembly, No tooling such as molds or dies are needed, It is possible to produce complex 3D shapes,

The barreling effect in open-die forging is the direct effect of what?

Friction between work and die surfaces

Which one of the following equipment types would usually be the least expensive to purchase and install to perform a give manufacturing process? General purpose or special purpose?

General Purpose

What manufacturing process is likely to result in the best surface finish?

Grinding

What are examples of property-enhancing operations?

Heat treatment, Sintering

All of the following are true about cold extrusion except: 1)Little or no waste of material 2)Greater strength due to better grain structure 3)It is impossible to produce tight tolerance 4)Must have uniform cross-section throughout the length 5)Capable of producing discrete parts

It is impossible to produce tight tolerance

All of the following are advantages of cold working except: 1)Heating of the work is not required 2)Better surface finish 3)Better accuracy and closer tolerances 4)Lower mechanical forces and power than hot working are required 5)Desirable directional properties in product

Lower mechanical forces and power than hot working are required

The size of the mold cavity should be slightly bigger than the actual part, to accommodate for which two: 1)shrinkage in the riser 2)mold expansion 3)metal expansion 4)machining allowance 5)shrinkage allowance?

Machining allowance and shrinkage allowance

What operations are classified as material removal processes?

Machining: Turning, Drilling, Grinding, Milling, etc

What is a micrometer appropriate for measuring ?

Part length ,Shaft diameter

What are two defects that are specific to sand casting?

Penetration and mold shift

All of the following are advantages of using hybrid technologies between machining and additive manufacturing, except: 1)Less floor space for the used machine 2)Avoiding additional part handling 3)Avoiding frequent setups 4)Possibility of making large plastic parts 5)No loss of part registration

Possibility of making large plastic parts

To drill a perfect hole, after drilling, the hole diameter should be finalized using what process?

Reaming

What manufacturing process is likely to result in the worst surface finish?

Sand casting

These are some of the design considerations in powder metallurgy, except: 1)Parts must have vertical or near vertical sides 2)Avoid too small acute angles in chamfers 3)Avoid features on part sides like holes and undercuts 4)Part geometry must permit ejection from die 5)Screw threads can be fabricated using the thread impression on the die

Screw threads can be fabricated using the thread impression on the die

What measurement instruments are considered to be graduated measuring devices?

Slide Caliper, Steel ruler, Vernier caliper, micrometers (has markings to measure)

A lathe has a set of specific spindle speeds that can be selected by a speed selector, while automatic feed and thread size can be selected from an index chart to engage carriage motion to feed rod or lead screw. (T/F)?

TRUE

A manufacturing process can be defined as a designed procedure that causes physical and/or chemical changes to a starting work material with the intention of increasing the value of that material. (T/F)?

TRUE

A sand-casting mold should be resistant to erosion, permeable to gases, thermally stable, collapsible and reusable. (T/F)?

TRUE

At elevated temperatures, any deformation process can be accomplished using lower forces and power, because both strength coefficient 'K' and strain hardening 'n' are reduced. (T/F)?

TRUE

Bolts and nails can be mass produced using a heading process, in which a wire is fed into a header to form heads at fastener ends and then cut those fasteners to length. (T/F)?

TRUE

Flashless forging is considered a precision forging process because starting work volume is equal to die cavity volume within very close tolerance. (T/F)?

TRUE

Gas, water and centrifugal automization are all mechanical automization processes to produce metal powders for powder metallurgy. (T/F)?

TRUE

In a lathe, the spindle rotates to produce cutting speed at tool edge, the carriage moves left and right to produce feed and the cross slide moves forward and backward to produce depth of cut. (T/F)?

TRUE

In a vertical milling machine, worktable moves side-to-side in the x-axis, saddle moves back and forth in the y-axis, while both the quill and the knee can provide movement up and down in the z-axis. (T/F)?

TRUE

Machining is a more superior process to casting to produce metal parts of different geometries and high precision and accuracy. (T/F)?

TRUE

Precision is the degree of repeatability in the measurement process: (T/F)?

TRUE

Product features are the aspect for which the design department is responsible for, while freedom from deficiencies is the aspect for which the manufacturing departments are responsible for. (T/F)?

TRUE

Rolling can be classified based on work-piece geometry into flat and shape rolling, and based on work temperature into hot and cold rolling. (T/F)?

TRUE

Sheet rolling doesn't use presses, while sheet metal is either bent into curved sections, or formed into long sections of specific cross-section shape produced by opposing rolls. (T/F)?

TRUE

Smaller particle sizes produce a larger angle of repose due to larger interparticle friction, in powder metallurgy. (T/F)?

TRUE

Strength constant equals to flow stress at strain rate = 1, and it decreases with the increase of temperature. (T/F)?

TRUE

Surface roughness is defined as the average value of the vertical deviations from the nominal surface over a specified surface length: (T/F)?

TRUE

The clearance in sheet metal cutting is required to be at an optimum value, to avoid large cutting force and excessive burr. (T/F)?

TRUE

The cutting action in machining involves both deformation and shearing of the work material to form a chip of a greater thickness after cutting. (T/F)?

TRUE

The existence of a CAD model is the core of rapid prototyping and additive manufacturing. (T/F)?

TRUE

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

TRUE

There is a single freezing and melting temperature for pure metals, however freezing and melting occur over a period of time. (T/F)?

TRUE

To machine a gear from a blank, one way is to use a cutter that has the same gear tooth form in a milling machine, while using a dividing head to index and advance the blank between each tooth. Another way is to use a hobbing machine that provides relative speed and feed motions between cutter and blank. (T/F)?

TRUE

Thread cutting on a lathe is a combination of shape forming and generating, since the tool has the geometry of the whole thread moves along the part. (T/F)?

TRUE (Thread cutting on a lathe is a combination of shape forming and generating, since the tool has the geometry of a single tooth that moves along the part.)

A larger positive rake angle increases the shear plane angle. This leads to a smaller chip thickness after cutting, and lower cutting force and power. (T/F)?

TRUE (larger α increases ϕ and decreases Tc leading to lower Fc and Pc --> review slide 32 and 33)

All of the following are features of climb milling except: 1)Tendency to push down the part 2)Longer tool life 3)Shorter chip length 4)Cutter rotates in the direction of feed 5)Tendency to lift the part

Tendency to lift the part

All of the following are true about the drawing process except: 1)Can produce electrical wires, metal bars, rod stock for fasteners and springs 2)Annealing is sometimes required between stages to relive work hardening 3)Is usually a cold working process 4)Starting end of the material needs to be pointed to allow insertion in the draw die opening 5)Tensile stress has the dominant role in the squeeze process inside the die

Tensile stress has the dominant role in the squeeze process inside the die

What is the correct definition of ultimate tensile strength, as derived from the results of a tensile test on a metal specimen?

The maximum load divided by the original area of the specimen (Fmax/Ao)

The shear strength of a metal is commonly determined by what test?

Torsion test

If engineering stress and true stress were measured simultaneously during a tensile test, which would have the higher value: 1)engineering stress 2)true stress 3)both 4)engineering stress w/in plasice region

True Stress

All of the following are good reasons to produce gears and bearings using powder metallurgy, except: 1)They can be mass produced with an economical competitive advantage over other processes 2)Gears and bearings can be made to net-shape or near net-shape using powder metallurgy 3)Using powered metallurgy will allow the porosity in gears and bearings to serve as reservoir for lubricant 4)Used raw material cost is less expensive than if metalworking processes were used 5)Gears and bearings geometry can be defined in two dimensions

Used raw material cost is less expensive than if metalworking processes were used

All of the following are true about sheet metal parts except: 1)They have the economy of scale as they can be mass produced 2)Relatively low cost per part 3)Good dimensional accuracy and surface finish 4)Excellent mechanical properties 5)Usually produced in hot working processes to avoid strain-hardening 6)Usually produced on stamping presses, but can be also produced without presses using other tools

Usually produced in hot working processes to avoid strain-hardening

All of the following are true about impression-die forging except: 1)flash forming fills the small gap between the two dies, forcing the metal to fill die cavity 2)favorable grain orientation in metal compared to machined parts 3)produces stringer parts than machining 4)result in higher production rates than machining 5)can produce very tight tolerances compared to machined parts 6)requires highly skilled workers under harsh conditions

can produce very tight tolerances compared to machined parts

Cupolas are only used for cast irons because:

cast iron has a high content of carbon that is also a part of the charge

When there is excessive buoyancy force on the core, we should:

hold the core in position by chaplets

All of the following are advantages of investment casting, except: 1)recovered wax can be reused 2)producing complex parts 3)no additional machining is usually required 4)inexpensive process 5)good surface finish

inexpensive process

All of the following is true about die casting except: 1)might use hot or cold-chamber machines 2)ejector pins required to remove part from die 3)suitable for low melting-point metals such as zinc, tin, lead and magnesium 4)not suitable for mass production 5)suitable for producing thin sections

not suitable for mass production

In expanded-polystyrene process, all the following is true except: 1)Foam pattern vaporizes upon metal pouring 2)sand is used in the mold 3)mold making process is simplified by not using tow mold halves, 4)patterns and castings can be mass produced 5)patterns are highly reusable

patterns are highly reusable