Question

Metallic core is more preferable than the sand core in the permanent mould casting.

(a) True

(b) False

This question was addressed to me in an interview.

Enquiry is from Permanent Mould Casting topic in division Special Casting Techniques of Casting-Forming-Welding I

Answer 1

The correct option is (b) False

To explain: Metallic core is not preferable that the sand core, because the metallic core cannot be complex with undercuts and the like. Also, the metallic core is to be withdrawn immediately after solidification; otherwise, its extraction becomes very difficult because of its shrinkage.