Modification of isothermal and cyclic oxidation behaviour of Ti–48Al–2Cr by ion implantation

AbstractThe effect of various elements added by ion implantation on the isothermal (up to 150 h) and cyclic (up to 1500 h) oxidation behaviour of γ-TlAl based intermetallics at 800°C in air is discussed. Ion implantation of Si, Nb, Ta, vv: and Al showed a large beneficial effect on the isothermal oxidation behaviour of Ti–48AI–2Cr. Similar results for these implanted elements were found during the initial period of cyclic oxidation experiments. For longer exposure times under cyclic oxidation conditions the corrosion scale formed on the Al and Si implanted specimens was especially prone to spallation. A minor positive effect was found for Ti, Mo, 1: Mn, and Cr. Oxidation of the specimens implanted with Si or Nb revealed similar results to those for the intermetallics alloyed with these elements. Furthermore, it is concluded that care should be taken when studying the cyclic corrosion damage of implanted specimens by gravimetric methods alone. Additional techniques are strongly recommended and often necess...