粉末冶金TiAl基合金显微组织及力学性能的研究

采用粉末冶金方法制备多种成分的ＴｉＡｌ基合金，并研究其显微组织及室温、高温力学性能，结果表明，采用粉末冶金方法能制备成分均匀、显微组织细小的Ｔｉ－Ａｌ－Ｃｒ－Ｎｂ系列合金。添加合金元素对粉末冶金ＴｉＡｌ基合金的显微组织具有显著影响。粉末冶金ＴｉＡｌ基合金的力学性能与其显微组织有密切的关系，显微组织越细小，其室温强度及延性越高，但在高温下，其屈服强度随晶粒尺寸增加而增加。所制备出的Ｔｉ－４７Ａｌ－３

Investigation of the Microstructures and Mechanical Properties of P/M TiAl-Based Alloys

The TiAl based alloys with various compositions were prepared by powder metallurgy(P/M), and their microstructures and mechanical properties studied. It was shown that homogeneous Ti Al Cr Nb alloys with fine microstructures can be obtained by means of powder metallurgy. The addition of alloying elements has a significant effect on the microstructure; for example additions of Cr and B will refine the grain size. The mechanical properties of the P/M Ti Al based alloys are related to their microstructures. The finer the microstructure, the higher the room temperature strength and ductility. At high temperatures the strength increases with increasing grain size. P/M processed Ti 47Al 3Cr was found to have good room temperature properties : an ultimate strength of 526 MPa and an elongation of 1 5%.