Explain why it is difficult to find a material with both a h

Explain why it is difficult to find a material with both a high stiffness and a high coefficient of thermal expansion

Solution

Due to the higher thermal coefficient of thermal expansion material experience large temperature changes, this refers to thermal stresses that activate failure by thermo-mechanical fatigue. To prevent this faliure, normally materials have low stiffness. So both high stiffness and high thermal coefficient type material are difficult to find.