Oxidation resistance improvement of low Al-content TiAl alloys by the halogen effect

Alloys on the basis of TiAl open new possibilities in the high-temperature technology (turbine blades for aeronautics, engine valves for automobiles...) due to their mechanical characteristics at high temperatures. However their use at temperatures above 700 °C is limited by their corrosion resistance. In order to improve the corrosion resistance, fluorination of the alloy can be accomplished by halogen ion implantation into the metal subsurface. The halogen effect improves the oxidation resistance by promoting an Al₂O₃ protective layer growth. Up to now the halogen effect was mainly applied to alloys with compositions close to 50 At.% aluminium. The goal of this project is to examine the potential of the halogen effect for alloys with Al-contents less than 48 At. %.