Q70 TO 100

Question 1

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

Answer 1

cast iron

Question 2

Surface cleaning of the solidified casting is most important in which one of the following casting processes:
(a) die casting, (b) liquid-metal casting, (c) sand casting, (d) shell casting, or (e) true centrifugal casting?

Answer 2

sand casting

Question 3

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 3

cast iron

Question 4

Which one of the following products would not be an appropriate application for zinc casting: (a)
automotive door handles, (b) model railroad locomotive, (c) structural beam, (d) toy car, or (e) trophy
statue?

Answer 4

structural beam

Question 5

Which one of the following casting processes are capable of the closest tolerances for parts of the same
size and metal: (a) investment casting, (b) sand casting, or (c) shell molding?

Answer 5

investment casting

Question 6

Machining allowance refers to additional material left on the casting to machine surfaces or geometric
features that cannot be achieved in the casting operation:

Answer 6

True

Question 7

The fabrication cost of the mold in expendable mold processes is a component in the total cost to produce
each casting because each casting requires its own mold, whereas in permanent mold casting processes,
the mold cost is apportioned over the quantity of parts made throughout the life of the mold:

Answer 7

True

Question 8

Which one of the following expendable mold processes is known as a precision-casting process: (a) antioch
process, (b) investment casting, (c) plaster-mold casting, (d) sand casting, and (e) shell molding?

Answer 8

b

Question 9

Only metals with low melting temperatures can be used in investment casting:

Answer 9

False

Question 10

Semipermanent-mold casting involves the use of a permanent mold but a sand core is used to create
internal features in the casting:

Answer 10

True

Question 11

Low-melting-point alloys of zinc and tin can be cast in cold-chamber die casting machines, but the
advantages of the hot-chamber process usually favor its use on these metals:

Answer 11

True

Question 12

Wheels and pulleys are examples of castings that are made by (a) centrifuge casting or (b) semicentrifugal
casting?

Answer 12

semicentrifugal casting

Question 13

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

Answer 13

centrifugal casting

slush casting

Question 14

A mold shift refers to a defect in sand casting caused by a sidewise displacement of the core inside the
casting before it solidifies:

Answer 14

False

Question 15

Which of the following metals is more difficult to cast: (a) cast iron or (b) cast steel?

Answer 15

cast steel

Question 16

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

Answer 16

tin

Question 17

What are the names of the upper and lower halves a sand casting mold?

Answer 17

Blank # 1 Cope
Blank # 2 Drag

Question 18

Among casting processes, which of the following provides the better surface finish, sand casting or
investment casting?

Answer 18

Investment Casting

Question 19

The conventional process for producing parts in powder metallurgy is to simultaneously press and sinter
metallic powders in a closed mold:

Answer 19

False

Question 20

Powder metal part shaping operations are generally considered to be net shape or near net shape
processes:

Answer 20

True

Question 21

For a given weight of metallic powders, the total surface area of the powders is increased by which two of
the following: (a) larger particle size, (b) smaller particle size, (c) higher shape factor, and (d) smaller shape
factor?

Answer 21

smaller particle size

higher shape factor

Question 22

For a given weight of metallic powders, the total surface area of the powders is increased by which two of
the following: (a) larger particle size, (b) smaller particle size, (c) higher shape factor, and (d) smaller shape
factor?

Answer 22

smaller particle size

higher shape factor

Question 23

As particle size increases, interparticle friction (a) decreases, (b) increases, or (c) remains the same?

Answer 23

decreases

Question 24

Of the following statements, which three are correct in the context of metallic powders: (a) porosity +
packing factor = 1.0, (b) packing factor = 1/porosity, (c) packing factor = 1.0 porosity, (d) packing factor
= porosity, (e) packing factor = bulk density/true density, and (f) packing factor = true density/bulk
density?

Answer 24

porosity + packing factor = 1.0

packing factor = 1.0

packing factor=bulk density/true density

Question 25

Blending of powders before pressing and sintering refers to which one of the following: (a) air is largely removed from the powders, (b) ceramic powders are intermingled with the metal powders to create cermets, (c) powders of different chemistries are intermingled, or (d) powders of the same chemistry but different particle sizes are intermingled?

Answer 25

powders of the same chemistry but different particle sizes are intermingled

Question 26

At what point in the PM part production sequence is the density of the powders the greatest: (a) after pressing, (b) after sintering, (c) before pressing, or (d) before sintering?

Answer 26

after sintering

Question 27

A single-action PM press is distinguished by which one of the following features: (a) lower punch presses upward, (b) presses from one direction, (c) presses from two directions, (d) produces one part per pressing cycle, or (e) upper punch presses downward?

Answer 27

presses from one direction

Question 28

Which of the following typifies the sintering temperatures used in powder metallurgy: (a) 0.5 Tm, (b) 0.8 Tm, or (c) Tm, where Tm = melting temperature of the metal on an absolute scale?

Answer 28

0.8 Tm

Question 29

Which one of the following processes combines pressing and sintering of the metal powders in one step: (a) cold isostatic pressing, (b) hot isostatic pressing, (c) liquid phase sintering, (d) metal injection molding, or (e) powder forging?

Answer 29

hot isostatic pressing

Question 30

When produced in large quantities, metal gears and bearings are well suited to PM because (1) the geometry is defined principally in two dimensions and (2) there is a need for porosity in the material to reduce weight:

Answer 30

False

Question 31

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:

Answer 31

True