Mechanical properties of oxidized porous MAX phase Cr₂AlC

Abstract

Cr₂AlC is one of a typical Mn₊₁AX_n (MAX) phase material, which shows unique metallic-like and ceramic-like properties. However, the mechanical properties before and after oxidation have not been fully elucidated. In this study, mechanical properties such as Young’s modulus and compressive strength of porous MAX phase Cr₂AlC annealed in air at high temperature were investigated. The specimens were annealed at temperatures from 1373 to 1473 K for 0 to 50 hours. Annealed Cr₂AlC was polished and observed by SEM, and the thickness of alumina was measured. The compressive strength of Cr₂AlC with a porosity of 53 vol% was 153 MPa when the alumina thickness was about 2.5 μm. Although the compressive strength is thought to increase due to the generation of the alumina layer, the thickness of the alumina layer and the compressive strength were not proportional.