Manufacturing Engineering Multiple Choice Questions on “Various Casting Process”.
1. Injection moulding is not a type of?
a) Die casting
b) Centrifugal casting
c) Squeeze casting
d) Investment casting
Answer: a
Clarification: In casting processes, there are two type of mould processes: 1. expendable mould processes, 2. permanent mould processes. Casting types such as, low-pressure PM casting, vacuum PM casting, die casting, squeeze casting, centrifugal casting, semi-centrifugal casting, injection moulding and compression moulding comes under permanent mould processes. Likewise, sand casting, shell casting, plaster casting, ceramic casting and investment casting are the types of expendable mould processes.
2. Which of the following statement is not correct about die casting?
a) It has close dimensional accuracy
b) Die has good life
c) It is very economical for large scale production
d) No need for removing the entrapped gases
Answer: d
Clarification: Gas entrapment is a very serious defect in all casting processes, and die casting too can go without them.
3. Which type of casting is preferred for making hollow pipes and tubes which are axisymmetric with concentric holes?
a) Centrifuging
b) True centrifugal casting
c) Semi-centrifugal casting
d) None of the mentioned
Answer: b
Clarification: Centrifugal casting is used to make hollow pipes. In this process, molten metal is poured in a mould which is rotating. The molten metal experiences centrifugal force and it is forced radially outward. The axis of rotation could be vertical, horizontal, or even inclined.
4. Which of the following casting is a combination of casting and forging?
a) Die casting
b) Centrifugal casting
c) Squeeze casting
d) Investment casting
Answer: c
Clarification: Squeeze casting is a combination of casting and forging. It is a process in which an alloy melt solidifies under the application of external pressure, in order to prevent the formation of shrinkage porosity.
5. In plaster mould casting the mould is made from?
a) CaSO4
b) CaSO3
c) CaSO2
d) Ca(SO4)2
Answer: a
Clarification: The mould is made from plaster of Paris whose chemical formula is CaSO4 Where Ca is calcium, S is sulphur and O represents oxygen.
6. In which casting process the sand is mixed with a thermosetting resin to form a mould?
a) Die casting
b) Centrifugal casting
c) Squeeze casting
d) Shell moulding
Answer: d
Clarification: The first step in the shell mold casting process is to manufacture the shell mold. The sand we use for the shell molding process is of a much smaller grain size than the typical greensand mold. This fine-grained sand is mixed with a thermosetting resin binder.
7. Which one of the following is a resin used in shell moulding technique?
a) Diphenyl aldehyde
b) Phenol formaldehyde
c) Methyl formaldehyde
d) Dimethyl formaldehyde
Answer: b
Clarification: Phenol formaldehyde and phenol formaldehyde are the two synthetic thermosetting resins used in shell moulding process.
8. Which casting is used to make hollow casting with thin walls?
a) Die casting
b) Centrifugal casting
c) Slush casting
d) Shell moulding
Answer: c
Clarification: Slush casting creates hollow castings with thin walls. This process gives thin-walled profiles with a superior surface finish.
9. In investment casting process which of the following is used for pattern making?
a) Ceramics
b) Molten wax
c) Silica
d) Plaster of paris
Answer: b
Clarification: Investment casting refers to the material being surrounded by a refractory material which is expendable, usually a ceramic. The wax carving is “invested” in the refractory material so to speak. Lox wax refers to a wax shape being made then surrounded with the refractory material to create a mold. The molten metal is then poured in the mold which melts the wax. As the wax runs out of the mold then the molten metal assumes the shape left by the impression of the wax object.
10. Which of the following is not an example of a precision casting process?
a) Plastic mould casting
b) Ceramic mould casting
c) Slush casting
d) Investment casting
Answer: d
Clarification: Precision casting is a lox wax casting (investment casting) process. The lox was method of precision casting is suitable for producing casting with complex shapes and high dimensional accuracy.