Question

For ____________ materials, there is no correspondence between tensile strength and hardness.

(a) soft

(b) hard materials

(c) steel

(d) carbon

The question was posed to me in examination.

This key question is from Aircraft Materials in division Testing Aircraft Materials of Aerospace Materials & Processes

Answer 1

Correct answer is (a) soft

To explain: There is a relation between hardness and tensile strength for materials like carbon and low alloy steels. The tensile strength can be predicted using hardness values. But for comparatively soft materials like aluminium alloys, this is not applicable.