Ce、Nb对Al_(66)Mn_9Ti_(25)金属间化合物形变和断裂行为的影响

Influence of Ce and Nb on the Behaviour of Deformation and Fracture for Intermetallic Compound Al 66 Mn 9Ti 25

本工作研究了微量Ｃｅ、Ｎｂ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。结果表明，添加微量Ｃｅ有显著的促进晶粒枝晶化和第二相弥散化作用，从而使微裂纹生成和扩展以及沿晶开裂受到一定程度的抑制，因而，压缩强度明显提高，压缩塑性也有改善。微量Ｎｂ的加入，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。

The influence of Ce and Nb on the microstructure,microcrack susceptiblity,microhardness,compression properties,fracture feature and defromed substructure of intermetallic compund Al 66 Mn 9Ti 25 was investigated.The dendritical grain and fine second phase are obtained by adding Ce into intermetallic compound Al 66 Mn 9Ti 25 ,by which the microcrack susceptiblity and intergranular failure are inhibited.For this reason,a significant improvement in compression strength is achieved,and a effect of enhancing ductility can be obtained.On the contray,by adding Nb into intermetallic compound Al 66 Mn 9Ti 25 ,the equiaxed grain and coarse second phase are exhibited.As a result,the compression peoperties are not improved.