How to Answer: What does 'cold working' refer to? What effect does this have on a material's properties?
Advice and answer examples written specifically for a Mechanical Engineer job interview.
13. What does 'cold working' refer to? What effect does this have on a material's properties?
How to Answer
Your interviewer will likely ask you knowledge-based questions to understand how well you are able to explain concepts to others. Be prepared for questions like this one by practicing a few possibilities ahead of time. In this case, cold working refers to processing a metal below its recrystallization temperature, which is usually one-third to one-half of the melting point. To do so, a high amount of pressure is applied in one of four general categories: squeezing, bending, shearing, and drawing. Doing so generally improves a material's tensile strength while reducing its ability to deform without breaking, also known as ductility. It can also be a way to shape metals into plates, sheets, and rods that are then used in manufacturing processes like machining.
Written by Jason Toby on October 12th, 2020
Answer Example
"Cold working refers to processing a material at a temperature below its recrystallization point. Processes like rolling, shearing, drawing, and bending are all examples of cold forming. Metals that have been processed this way will be stronger than they were originally, but they will also become more brittle. I believe that for some materials, these effects can be reduced with heat treatment after being cold worked, which allows the material to release the stored energy caused by cold working and become ductile again."
Written by Jason Toby on October 12th, 2020