轻质化MA/ODS镍基高温合金高温氧化行为

High temperature oxidation behavior of low density MA/ODS nickel-based superalloy

采用机械合金化(MA)和真空烧结工艺制备了Y2O3质量分数为2%～20%的氧化物弥散强化(ODS)镍基高温合金,在1 000℃空气中对合金试样进行100h的静态氧化实验,研究了Y2O3含量对合金高温氧化性能的影响与作用机制.结果表明:适量稀土氧化物Y2O3的加入(质量分数≤5%)可促进完整Cr2O3氧化膜的形成,提高氧化膜与合金基体的附着力,改善氧化膜的抗剥落性,减缓合金在1 000℃的氧化速度,从而有效提高合金的抗高温氧化性能.但过量添加则会使其抗氧化性能迅速下降.

ODS （oxide dispersion strengthened） nickel-based superalloy with different content of nano Y203（2%-20%） as dispersion phase was prepared by mechanical alloying （MA） and vacuum sintering. Samples of the alloy were oxidized at 1 000 ℃ in static air for 100 h. The effect and mechanism of Y2 O3 content on the high temperature oxidation performance of the alloy were investigated. The re- sults show that appropriate amount of rare earth oxide Y203 （≤5%） can promote the complete formation of Cr203 oxide film, enhance the adhesion of oxide film/substrate and improve the oxide film anti- flaking, so that vastly slows down the oxidation rate at 1 000℃, which effectively improve the high temperature oxidation resistance of the alloy. But excessive content can make its antioxidant properties fall rapidly.