Y2O3含量对Ni-20Cr-5Al合金高温抗氧化性能的影响

摘要

将镍、铬、铝粉按比例混合后,再添加不同质量分数(0~5%)Y2 O3粉作为弥散相,采用粉末冶金技术制备了Ni-20Cr-5Al-xY2 O3(质量分数/%)氧化物弥散强化镍基高温合金,并在1150℃下进行了100 h恒温氧化试验,研究了Y2 O3含量对其高温抗氧化性能的影响.结果表明:Y2 O3质量分数为0~5%时,试验合金在长时间氧化后均具有较好的高温抗氧化性能;Y2 O3的添加有利于试验合金表面氧化膜中Cr2 O3的形成,但其质量分数为1%~5%时会同时降低氧化膜的致密性和附着性,从而降低合金的高温抗氧化性能.%The 0 -5wt% Y2O3 powders were added to the mixed powders of nickel,chromium and aluminum at a certain ratio as a dispersion phase,and then the Ni-20Cr-5Al-xY2O3 (mass/%)oxide dispersion strengthened Ni-based superalloys were prepared by the powder metallurgy technology.The isothermal oxidation tests of the alloys were carried out at 1150 ℃ for 100 h and the effects of Y2O3 content on the high temperature oxidation resistance of the alloys were studied.The results show that the experimental alloys all had an excellent oxidation resistance after oxidation for a long time with the Y2O3 content of 0-5wt%.The addition of Y2O3 can promote the formation of Cr2O3 in the surface oxidation films of the experimental alloys,but also reduced the density and adhesion of the oxide films with the addition of 1wt%-5wt%,resulting in the decrease of the high temperature oxidation resistance of the alloys.