Casting

Question 1

What is the definition of casting? (definitely will be on the test)

Answer 1

The process of pouring molten metal into a prepared mold allowing metal to solidify into a desired shape.

Question 2

Once the steel is made what are the 3 options for making components that are used in the industry?

Answer 2

1) Castings: melting and resolidifying the alloy

2) Wrought: mechanical force shaping

3) Powder metallurgy: metal powder that is mixed with a binder and shaped under high pressure and temperature

Question 3

The most widely used molds are made of ___________ and consist of the top half of the mold called the __________ and the
bottom half of the mold called a ____________. Often a ____________ is required which allows for hollow portions in the
part.

Answer 3

Sand, cope, drag, core

Question 4

Why are patterns typically made larger than the part itself?

Answer 4

To compensate for the shrinking of the part as it cools and solidifies

Question 5

What are the 4 different casting methods?

Answer 5

1) Sand casting: molds made of sand allow for complex geometry and large parts.

2) Die casting: metal mold allows for high volume production with a precise surface finish

3) Investment casting: wax mold used for intricate parts. Also known as precision casting.

4) Centrifugal casting: mold rotates creating cylindrical shapes using centrifugal force

Question 6

What can a mold pattern be made of?

Answer 6

1) Wood
2) Metal
3) Wax
4) Sand
5) Clay
6) Foam

Question 7

What does anisotropic mean?

Answer 7

Not equal in all directions

Question 8

An important problem in casting is to produce a uniform, equal fine grain structure. How can this be achieved?

Answer 8

1) Chilling
2) Inoculating: adds soluble impurities
3) Ultrasonic vibration: promotes nucleation points and breaks crystals

Question 9

What are some discontinuities that may exist in casted parts and how can they be detected?

Answer 9

1) Cavities: detected using ultrasonic detection
2) Defective surface, inclusion: liquid penetrant detection
3) Hot crack: ultrasonic detection

Question 10

Grain size affects the ___________ properties of steel

Answer 10

Mechanical

Question 11

What are the 2 types of centrifugal casting?

Answer 11

1) Horizontal
2) Vertical

Question 12

What is the one casting defect that does not appear in forging?

Answer 12

Incomplete casting due to short pour