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本工作研究了微量稀土元素镧、钇对Ａｌ６６Ｍｎ９Ｔｉ２５金属间化合物显微组织、微裂纹生成及扩展倾向、维氏硬度、压缩性能、断裂特征、变形亚结构的影响。研究工作表明，添加微量镧可促进晶粒枝晶化和第二相弥散化，起到一定的抑制微裂纹生成和扩展以及沿晶开裂的作用，同时，还可增强位错的可动性，因之压缩塑性得到改善。微量钇的加入，虽能增强位错可动性，但显微组织仍保持等轴状晶粒和粗大第二相，压缩性能未能改善。本文讨论了显微组织、微裂纹、断裂特征与压缩性能的内在联系，结合有关理论，探讨了稀土元素的作用机理。
In this work, the effects of rare earth elements such as lanthanum and yttrium on the microstructure, microcrack generation and propagation tendency, Vickers hardness, compressive property, fracture characteristics and deformation substructure of Al66Mn9Ti25 intermetallic compound were studied. The research work shows that the addition of trace amount of lanthanum can promote the dendrite crystallization and the second phase dispersion, play a certain role in inhibiting the formation and propagation of microcracks and cracking along the crystal, meanwhile, it can enhance the dislocation mobility, The plasticity of compression is improved. Although the addition of trace amount of yttrium can enhance the dislocation mobility, the microstructure still maintains the equiaxed grains and the coarse second phase, and the compressive property can not be improved. In this paper, the intrinsic relations between microstructure, microcrack, fracture characteristics and compressive properties are discussed. The mechanism of action of rare earth elements is discussed with the related theory.