High-temperature oxidation behavior of double glow plasma Cr-Y alloyed layers on Ti2AlNb alloy

A Cr -Y alloyed layer was synthesized on the surface of Ti2AlNb by double glow plasma surface alloying technique. The morphology, phase composition and oxidation behaviors at 750 degrees C, 800 degrees C, and 850 degrees C of Cr -Y alloyed layers were systematically investigated. The results illustrated that Cr -Y alloyed layer was approximately 10 mu m thick, which the morphology of alloyed layer was uniform and compact, with a flat and uniform interface to the matrix. Oxidation kinetics for the Cr -Y alloyed layer approximately followed the parabolic law, with an oxidation weight gain significantly lower than that of Ti2AlNb. The predominant oxides of Cr -Y layer were CrNbO4, Cr2O3, and Y2O3, which effectively hindered oxygen diffusion into the substrate.