Question

A thin water cooled mould always tends to make a casting of soft and ductile nature.

(a) True

(b) False

The question was posed to me by my school teacher while I was bunking the class.

My doubt stems from Solidification with Constant Surface Temperature in chapter Cooling and Solidification of Casting-Forming-Welding I

Answer 1

Correct option is (b) False

To explain I would say: Thin wall of the mould and the water cooling makes the solidification rate fast, which produces fine grain structure of the casting. The fine grain structure of casting is always brittle and hard in nature because the process is somewhat similar to quenching which also produces a casting of brittle nature.