Question

A gap of finite thickness at the interface of mould and metal always increases the heat flux.

(a) True

(b) False

This question was posed to me by my college director while I was bunking the class.

The origin of the question is Solidification with Predominant Interface Resistance in chapter Cooling and Solidification of Casting-Forming-Welding I

Answer 1

Right option is (b) False

Easy explanation: A gap of finite thickness separating the mould and casting interface always results in lowering of heat flux. It is the most important phenomena for controlling the solidification of the casting in the metallic mould. The time of its formation and distribution affects the temperature distribution in the casting.