Influence of Ion Implantation of Several Elements on Oxidation Behavior of TiAl
TiAl-based alloys have attractive properties as light weight heat-resisting material. In the present work, the influence of Cu, Zn, Ag and Se on the oxidation behavior of TiAl was investigated by ion implantation at acceleration voltage of 50 kV and ion doses of 1019 to 2x1021 ions/m2. The oxidation behavior was assessed by a cyclic oxidation test at 1200 K in a flow of purified oxygen under atmospheric pressure. The oxidation products were analyzed by conventional methods including X-ray diffractometry, SEM and EPMA. The implantation of Zn and Cu improves the oxidation resistance significantly by forming virtually Al2O3 scales, while Ag and Se enhance the oxidation. The improvement by Zn is attributable to the formation of complex oxide of Zn in the initial stage of oxidation. The oxygen partial pressure under the layer seems to be very low, resulting in the formation of alumina scale due to a selective oxidation of Al. The influence of Cu is not certain. The influence of Ag and Se is explained in terms of Al depletion in the implanted layer.
Shigeji Taniguchi, Toshio Maruyama, Masayuki Yoshiba, Nobuo Otsuka and Yuuzou Kawahara
M. Yoshihara et al., "Influence of Ion Implantation of Several Elements on Oxidation Behavior of TiAl", Materials Science Forum, Vols. 522-523, pp. 633-640, 2006