Effect of texture on oxidation resistance of Ti3AlC2

Oxidation resistance of textured Ti3AlC2 ceramics was measured in the temperature range 1273-1573 K It was found that the oxidation was markedly anisotropic and the samples exhibited a better oxidation resistance when tested along a direction transverse to the c-axis. This behavior was attributed to the rapid diffusion of A1 within its basal planes to form a passivating Al2O3 scale and it respected Ellingham diagrams. The scales formed had different compositions depending on the testing direction, this response was clearly resulting from the crystal lographic orientation. Even at 1473 K after 20 h exposure, the samples tested in a direction transverse to the c-axis showed a reduced weight gain which was 45 times lower than one seen on a basal plane.