Influence of Nb ion implantation on oxidation behavior of gamma-TiAl alloys in flowing air

gamma-TiAl alloys were implanted with Nh ions with energy of 50 keV at a do se of 1.2 x 10(21) ions/m(2). Cyclic oxidation testing on as-received and N b+-implanted TiAl alloys was conducted at 1123 K in air with a flow velocit y of 12 mm/s. At the initial oxidation stage, a TiO2/Al2O3 mixed scale is f ormed 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 ox idation test for up to 1100 ks, severe scale spallation occurs on as-receiv ed TiAl alloys. In contrast, Nb+-implanted TiAl alloys exhibit excellent cy clic oxidation resistance in flowing air.