中文摘要：

通过粉末冶金方法制备了Ni-20Cr-5Al和Ni-20Cr-5Al-0.2Y2O3（质量分数/%,下同）合金,将Ni-20Cr-5Al-0.2Y2O3合金在不同温度（500~1 100℃）进行预氧化处理,然后将未预氧化及预氧化合金在1 150℃下循环氧化15h,研究了Y2O3的添加和不同预氧化温度对合金抗高温循环氧化性能的影响。结果表明：添加0.2%Y2O3后提高了Ni-20Cr-5Al合金的抗高温循环氧化性能;预氧化可以有效提高Ni-20Cr-5Al-0.2Y2O3合金的抗高温循环氧化性能,其中预氧化温度为700℃的合金有最优的抗高温循环氧化性能,其原因是经过预氧化处理的合金表面形成了致密的保护性氧化膜,阻止了氧化的进一步进行。

英文摘要：

Ni-20Cr-5A1 and Ni-20Cr-5A1-0. 2Y2O3 （mass fraction/%） alloys were prepared by powder metallurgic technology. The Ni-20Cr-5AF0.2Y2O3 alloy was first pre-oxidized at different temperatures from 500 ℃ to 1 100 ℃, and then the un-oxidized and pre-oxidized alloys were cyclic oxidized at 1 150 ℃ for 15 h. The effects of Y2O3 and pre-oxidation temperature on the high-temperature cyclic oxidation resistance of the alloys were studied. The results show that the high-temperature cyclic oxidation resistance of Ni-20Cr-5A1 alloy was improved with the addition of 0.2wt% Y2O3. The pre-oxidation can improve the high-temperature oxidation resistance of Ni-20Cr-5A1- 0.2Y2O3 alloy effectively. Furthermore, when the pre-oxidation temperature was 700 ℃, the alloy achieved the best high-temperature cyclic oxidation resistance. The reason is that a dense protective oxide scale was formed on the surface of the alloy after pre-oxidation, which prevented the alloy from the further oxidation.