The Effect of Niobium Ion Implantation on the Oxidation Behavior of a γ-TiAl-Based Intermetallic

摘要

The effect of niobium implantation (2 x 10~(16) and 10~(17) ions/cm~2) on the oxidation behavior of a γ-TiAl-based intermetallic alloy Ti-48Al-2Cr in air at 800℃ has been examined. Isothermal studies with exposure times up to 200 hr and cyclic-oxidation tests up to 800 hr revealed a negligible effect for the low implantation dose. However, a remarkable decrease in oxidation rates was observed for the material implanted with 10~(17) Nb ions/cm~2. The improvement in the oxidation resistance appeared to be similar to that obtained by alloying of the intermetallic with a few atomic percent niobium. Possible mechanisms for the effect of niobium on the oxidation resistance of TiAl-base intermetallics are discussed in view of the results obtained for the implanted material.