High-purity, dense Cr 2 AlC compounds were synthesized by hot pressing a mixture of CrC X (x = 0.5) and Al powders. Oxidation at temperatures between 900 and 1200°C in air for up to 480 h resulted in the formation of a thin Al 2 O 3 layer. The consumption of Al to make the Al 2 O 3 layer led to the enrichment of Cr immediately below the Al 2 O 3 layer, resulting in the formation of an underlying Cr 7 C 3 layer. At the same time, carbon escaped from the Cr 2 AlC into the air. During the initial stage of oxidation, oxygen diffused inward to form the Al 2 O 3 layer, which vastly improved the oxidation resistance of Cr 2 AlC from the initial stage of oxidation.

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