Question

Silicon carbide is widely used as refractory material in the mould making for casting processes.

(a) True

(b) False

This question was addressed to me in an interview.

The question is from Foundry Fluxes and Refractories topic in section Foundry Introduction & Materials of Casting-Forming-Welding II

Answer 1

The correct answer is (b) False

The best I can explain: Silicon carbide is a good refractory material, but cannot be used in mould making process because it is highly reactive with oxygen and gets burns itself during oxidation. To avoid such oxidation problems, zirconia is preferred which can also bear very high temperatures and perfectly acts as a refractory material.