Question

Minimization of friction between the mould and casting surface can reduce the chances of tearing of thin parts of the casting.

(a) True

(b) False

The question was posed to me during an interview for a job.

My question is taken from Solidification with Predominant Resistance in Mould topic in chapter Cooling and Solidification of Casting-Forming-Welding I

Answer 1

Correct option is (a) True

To explain I would say: During solidification, prevention of sticking and tearing of the initial thin shell of the casting is a major consideration. To minimize the shell sticking and tearing, friction between the casting surface and mould wall must be kept below a critical level which depends upon the shell strength of the casting.