EFFECT OF CHLORINE ON OXIDATION OF TiAl-BASE ALLOY
氯对TiAl基合金高温氧化行为的影响

The effects of MnCl2 spraying and Cl ion implantation on the isothermal oxidation of TiAl alloy at 950 have been studied. The oxide scale on TiAl was a mixture of TiO2 and Al2O3 grains. The oxidation rate was decreased by 4 orders of magnitude after a little amount of MnCl2 was sprayed on TiAl. The scale on MnCl2 sprayed TiAl mainly consisted of Al2O3 . The reason lay in that titanium in the alloy reacted with Cl at the beginning of oxidation to form titanium chloride which vaporized from alloy surface. A layer of compact Al2O3 scale was formed on the surface of the alloy and prevented the outward diffusion of Ti in the alloy . Ion implantation doses of 1101511017Cl\|/cm2 decreased the oxidation rate apparently in the initial period of oxidation and prevented the formation of TiO2. But the amount of TiO2 in the scale increased with increasing oxidation time. Besides Al2O3, a little amount of TiO2 was also formed on Cl\|\|implanted TiAl at the beginning of oxidation and thus suppressed the formatio