Abstract
Titanium alloys cannot be used for structural materials at a temperature over 873 K because of their poor oxidation resistance. In this study, the Al3Ti layer was formed on the surface of the titanium plates by aluminizing on purpose to improve the oxidation resistance. The layers of intermediate phases of TiAl2, TiAl and Ti3Al and their uneven interface were found in a specimen which was heat treated at 1173 K. They are effective for relieving the thermal stress between the outside Al3Ti layer and the inside titanium plate. The aluminum and chromium combined diffusion treatment is effective to inhibit the formation of crack within the Al3Ti layer and to suppress the growth of intermediate phase which is believed to deteriorate the oxidation resistance.
