Influence of Nb Ion Implantation on Oxidation Behavior of γ-TiAl Alloys in Flowing Air

Abstract

γ-TiAl alloys were implanted with Nb ions with energy of 50 keV at a dose of 1.2×10²¹ ions/m². Cyclic oxidation testing on as-received and Nb⁺-implanted TiAl alloys was conducted at 1123 K in air with a flow velocity of 12 mm/s. At the initial oxidation stage, a TiO₂/Al₂O₃ mixed scale is formed on the as-received TiAl alloys whereas for Nb⁺-implanted TiAl alloys, an Al₂O₃-rich layer is observed present in the scale. During the cyclic oxidation test for up to 1100 ks, severe scale spallation occurs on as-received TiAl alloys. In contrast, Nb⁺-implanted TiAl alloys exhibit excellent cyclic oxidation resistance in flowing air.