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通过真空感应熔炼以单一和复合两种方式在Ni-10Cr-5Al合金中添加1%(质量分数)的稀土Y,La,Ce,Y+La,Y+Ce以及La+Ce。研究了不同稀土元素添加类型对Ni-10Cr-5Al合金在1000℃下空气中氧化行为的影响。采用热重法并结合X射线衍射、扫描电子显微镜、能谱仪等分析手段,检测了合金氧化后的微观结构演变和元素分布,进而探讨了不同稀土添加类型的影响作用。结果表明:经1000℃氧化200 h后,不同合金的稳态氧化过程均服从抛物线规律;合金添加稀土后,虽然只有单一添加Y对合金的抗氧化性能有所提高,而其他添加方式均增大了合金的氧化速率,其中复合添加的方式加剧了合金沿晶界的内氧化,但添加稀土可以抑制θ-Al_2O_3向α-Al_2O_3的转变,有利于提高合金氧化膜的抗剥落性能。
1% (mass fraction) rare earths Y, La, Ce, Y + La, Y + Ce and La + Ce were added to the Ni-10Cr-5Al alloy by vacuum induction melting in both single and composite ways. The effects of different rare earth addition types on the oxidation behavior of Ni-10Cr-5Al alloy at 1000 ℃ in air were studied. Thermal gravimetric analysis, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy and other analytical techniques were used to examine the microstructure evolution and elemental distribution of the alloy after oxidation. Then, the effects of different rare earth addition types were discussed. The results show that the steady-state oxidation processes of different alloys obey the parabolic law after being oxidized at 1000 ℃ for 200 h. Although the oxidation resistance of the alloy increases with the addition of rare earth, the other additions increase However, the addition of rare earth can inhibit the transformation of θ-Al_2O_3 to α-Al_2O_3, and improve the anti-spalling property of the alloy oxide film.