Question

In centrifugal casting, when internal cavity or complex hollow section is required, the core is usually made of

• A. Metal alloy
• B. Plastic
• C. Wood
• D. Sand or refractory material

Hint:

Cores are almost always made of sand/refractories because they must survive the heat but be easy to remove later.

Answer 1

The Correct Option is D

Step 1: Concept Centrifugal casting uses rotation to distribute molten metal. While true centrifugal casting doesn't use cores, semi-centrifugal or centrifuging often does.

Step 2: Meaning A core is a removable insert used to create internal cavities or hollow features.

Step 3: Analysis The core must withstand the heat of the molten metal and the high G-forces of rotation without melting or collapsing.

Step 4: Conclusion Sand or refractory materials provide the necessary heat resistance and collapsibility required for these casting conditions. Final Answer: (D)