Ion implantation technique as research tool for improving oxidation behaviour of TiAl based intermetallic alloys

The effect of various elements added by ion implantation on the isothermal (up to 150 h) and cyclic (up to 1500 It) oxidation behaviour of gamma-TiAl based intermetallic alloys at 800 and 900 degrees C in air has been studied . At 800 degrees C ion implantation of Si, Nb, Ta, W, and Al showed a large beneficial effect an the oxidation behaviour of Ti-48Al-2Cr. A minor effec t was found far Ti, Mo, Y; Mn, Pt, Rh, and Cr. More important was the oxida tion of specimens implanted with Si or Nb, which revealed similar results t o those for the intermetallic materials alloyed with these elements, i.e. T i-47Al-2Cr-0.2Si and Ti-48Al-2Cr-2Nb. From this point of view it was conclu ded that the ion implantation technique cart be employed as a 'screening' t est for evaluating the effect of possible alloying additions. As a followup this technique was used as a research tool to study the effect of Nb, Pt, Rh, Si, Ta, and Wort the oxidation behaviour of two types of Nb bearing TiA l based intermetallic alloys, i.e. Ti-48Al-2Cr-2Nb and Ti-48Al-2Mn-2Nb, at 900 degrees C in air. In this case, no significant effect of the implanted elements on the is other mal and cyclic oxidation behaviour was found.