Manufacturing Engineering Multiple Choice Questions on “Expendable Mold, Permanent-Pattern Processes”.
1. Applications of sand casting include __________
a) machine bases
b) large turbine impellers
c) propellers
d) automobile gears
Answer: d
Clarification: Typical applications of sand casting include machine bases, large turbine impellers, propellers, plumbing fixtures, and a wide variety of other products and components.
2. Sand casting consists of __________
a) placing a pattern in sand to make an imprint
b) incorporating a gating system
c) removing the pattern and filling the mold cavity with molten metal
d) all of the mentioned
Answer: d
Clarification: Basically, sand casting consists of
a) placing a pattern (having the shape of the desired casting) in sand to make an imprint,
b) incorporating a gating system,
c) removing the pattern and filling the mold cavity with molten metal,
d) allowing the metal to cool until it solidifies,
e) breaking away the sand mold, and
f) removing the casting.
3. Which of the following are used to mold the sand mixture into shape of the casting and may be made of wood, plastic, metal?
a) Vents
b) Patterns
c) Cores
d) Chills
Answer: b
Clarification: Patterns are used to mold the sand mixture into the shape of the casting and may be made of wood, plastic, or metal. The selection of a pattern material depends on the size and shape of the casting, the dimensional accuracy and the quantity of castings required, and the molding process.
4. Which of the following fill the flask uniformly with sand under a high-pressure stream?
a) Sandslingers
b) Patterns
c) Cores
d) Chills
Answer: a
Clarification: A sand slinger is an automatic machine equipped with a unit that throws sand rapidly and with great force into the mould box. Sand slingers fill the flask uniformly with sand under a high-pressure stream, they are used to fill large flasks and are operated typically by machine.
5. In which of the following technique, sand is compacted by a controlled explosion or instantaneous release of compressed gases?
a) vacuum molding
b) impact molding
c) blow molding
d) rotational molding
Answer: b
Clarification: In impact molding, the sand is compacted by a controlled explosion or instantaneous release of compressed gases whine in vacuum molding the pattern is covered tightly with a thin sheet of plastic.
6. In which of the following technique, the pattern is covered tightly with a thin sheet of plastic?
a) vacuum molding
b) impact molding
c) blow molding
d) rotational molding
Answer: a
Clarification: In vacuum molding (also known as the V process), the pattern is covered tightly with a thin sheet of plastic while in impact molding, the sand is compacted by a controlled explosion or instantaneous release of compressed gases.
7. Shell-molding applications include ____________
a) small mechanical parts requiring high precision
b) such as gear housings
c) cylinder heads
d) all of the mentioned
Answer: d
Clarification: Shell-molding applications include small mechanical parts requiring high precision, such as gear housings, cylinder heads, and connecting rods. The process also is used widely in producing high-precision molding cores.
8. Along with plaster of paris, with the addition of tale, which of the following is added in the plaster-molding process?
a) copper
b) iron
c) silica
d) calcium