ＴｉＡｌ金属間化合物の高温酸化に及ぼすレーザー表面処理の効果

Abstract

The effect of laser surface treatment on the resistance of high-temperature oxidation of TiAl intermetallic compound was studied using 500W CO2 gas laser equipment. The diameter of the laser spot was about 100μm and scanning was 95mm·s-1. Laser surface treatment formed a layer solidified by rapid quenching on the TiAl surface. The oxidation of TiAl at 1273 K in a pure O2 atmosphere, which followed the parabolic rate law, was reduced to less than half by laser surface treatment. Scale formed on the laser surface-treated TiAl after the oxidation experiment was thinner than that formed on nontreated TiAl and contained a continuous, dense Al2O3 layer. No such continuous Al2O3 layer was observed for scale formed on nontreated TiAl, indicating that, for laser surface-treated TiAl, the continuous Al2O3 layer in the scale acted as a diffusion species barrier, inhibiting scale growth.