Oxidation of Ti2AlC bulk and spray deposited coatings

The oxidation behaviour of Ti2AlC bulk and high velocity oxy-fuel spray deposited coatings has been investigated for temperatures up to 1200 degrees C. X-ray diffraction and electron microscopy show that bulk Ti2AlC forms a continuous layer of alpha-Al2O3 below a layer of TiO2 at temperatures as low as 700 degrees C. Oxidation of the Ti2AlC coatings is more complex, and also involves the phases Ti3AlC2, TiC, and TixAly, formed during the spraying process. alpha-Al2O3 is observed, however, it is unevenly distributed deep into the material, and does not form a continuous layer essential for good oxidation resistance. (C) 2010 Elsevier Ltd. All rights reserved.