Question

What is the tensile strength of aluminum oxide?

(a) 175 MPa

(b) 210 MPa

(c) 415 MPa

(d) 550 MPa

The question was asked in a national level competition.

I'm obligated to ask this question of Ceramics in chapter Non Metallic Materials of Engineering Material & Metallurgy

Answer 1

The correct answer is (b) 210 MPa

The best I can explain: Alumina has a medium tensile strength of 210 MPa and Young’s modulus of 3.86 * 105. Silicon carbide has a tensile strength of 175MPa, which is lower than alumina. The tensile strength of silicon nitride and sialons are 415 MPa and 550 MPa respectively.