Casting MCQ

Best process for small nonferrous casting with thin sections

Die casting

A flask is

Box which holds cope and drag

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

Metals typically used in die casting

Cast iron, tin and zinc

Permanent mold operations casting

Centrifugal and die casting

In foundry work a runner is

Channel in the mold leading from the down sprue to the main mold cavity

The main function of the down sprue is to eliminate the cold shut defect in the product

False

Not advantages of die casting over sand

Higher melting temperature metals and larger parts can be cast

Properties which make a material more suitable for sand casting

Low melting point and high fluidity

Material suitable for making die casting products

Metals that can melt at low temperatures

Why is green mold called that

Moisture is contained in the mold

Material suitable for lost foam casting

Polystyrene

Super heat is the temperature difference between

Pouring temperature and melting point

Liquid is a temperature at which an alloy

Starts to freeze Melts completely

Cooling curve of pure metal shows a relationship between

Temperature-time

In sand casting, the volumetric size of the pattern is (a) bigger than, (b) same size as, or (c) smaller than the cast part?

bigger than

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?

greater than

Most widely used casting process

sand casting

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?

time between pouring and complete solidification