Influence of alloy compositions on the halogen effect in TiAl alloys

F‐implantation concentration profile simulations were carried out and the influence of the ion fluence, implantation energy as well as the alloy composition were investigated. For alloys with Al contents between 40 and 50 at% the conditions to get the halogen effect were assessed by thermodynamic calculations. According to the thermodynamic predictions the implantation parameters were kept constant in this composition range. The implanted alloys were exposed in laboratory air over 4000 h. With the implantation parameters used (20 keV and 1 × 10¹⁷ F/cm²), the halogen effect was found to be efficient over 4000 h. The oxide growth kinetic constants were measured and vary between 1.2 and 2.7 × 10^?13 g²/cm⁴/s.