采用粉末冶金工艺制备 Ni-20Cr-2.5Al、Ni-20Cr-2.5Al-0.8Y2O3、Ni-20Cr-2.5Al-3Y2O3镍基高温合金,研究不同含量的Y2O3对Ni-20Cr-2.5Al合金在1000℃时的高温氧化行为.结果表明:加入Y2O3后,试验合金的晶粒明显细化,Cr在Ni中的固溶度也有所提高;试验合金的氧化增量随着Y2O3含量的增加呈现降低的趋势,高温抗氧化能力得到提高;试验合金氧化膜的均匀性、紧密度和与基体结合力得到提高,氧化膜的成分主要是 Al2O3.当 Y2O3质量分数为3 %时, Ni-20Cr-2.5Al合金的高温抗氧化能力最好.%On preparation of Nickel based superalloy Ni-20cr-2.5Al, Ni-20Cr-2.5Al-0.8Y2O3, Ni-20Cr-2.5Al-3Y2O3was prepared using powder metallurgy technology. The effect of different Y2O3 content on the oxidation behavior in air at 1 000 ℃ was studied.The results showed that after addition of Y2O3,test alloy grain refinement and solid solubility of Cr in Ni were obviously improved.The test alloy oxidation weight decreased with the increase of Y2O3content indicating that the resistance to high temper-ature oxidation was improved.The test alloy anodic coating is compact and uniform with better integration with the matrix.The main components of the oxide film was Al2O3.The best resistance to high tempera-ture oxidation of the Ni-20cr-2.5Al alloy was achieved at Y2O3content of 3 %.
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