稀土元素在NiAl合金中的作用

EFFECTS OF RARE EARTH ELEMENTS ON NiAl-BASED ALLOYS

为了改善NiAl合金的室温塑性,近年来研究了Sc,Y,Ce,Nd,Dy,Ho和Gd 7种稀土元素分别对NiAl共晶合金组织结构、力学性能和抗氧化性能的影响.结果表明,适量稀土元素加入到NiAl共晶合金中,能够显著细化合金组织和晶粒,有效改善NiAl共晶合金的室温和高温拉伸塑性和强度,并提高其抗氧化性能;而过量的稀土元素使该合金的力学性能和抗氧化性能降低.

During the past years, in order to improve the ductility at room temperature of NiAl- based alloys, Guo et al. have investigated the effects of rare earth elements Sc, Y, Ce, Nd, Dy, Ho and Gd on the microstructure, mechanical properties and oxidation resistance of NiAl-based eutectic alloys. The results indicate that the appropriate addition of rare earth element in the NiAl-based alloys can significantly refine the microstructure and grains, effectively improve the tensile ductilities and strengths at room and elevated temperatures, and reasonably improve the oxidation resistance. However, an excess addition of rare earth element will weaken the mechanical properties and oxidation resistance of the alloys.