Question

Which of the following is not desirable in casting design for minimum stress concentration?

(a) Roundness of external corners

(b) Local metal accumulations

(c) No abrupt changes in casting walls

(d) Uniform thickness of casting walls

I got this question during an interview.

My question is from Product Design for Sand Castings topic in chapter Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I

Answer 1

Correct option is (b) Local metal accumulations

Easiest explanation: In casting design for minimum stress concentration and good casting consistency, local metal accumulations and massive elements should be avoided as much as possible to restrict the generations of shrinkage defects in the castings, which can also be caused by having of low strength of casting at a higher temperature.