Microstructure and mechanical properties of Ti43Al6Nb alloys with different zirconium contents  

作　　者：Xiao-Ye Zhao Rui-Run Chen Yong Yang Jing-Jie Guo Hong-Sheng Ding Yan-Qing Su Heng-Zhi Fu 

机构地区：[1]School of Materials Science and Engineering,Harbin Institute of Technology,Harbin,150001,China

出　　处：《Rare Metals》2023年第6期2047-2056,共10页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (Nos.51274076, 51425402 and 51331005)。

摘　　要：Ti43Al6Nb-xZr alloys with different additions of zirconium were prepared by vacuum arc melting furnace.The microstructure and compressive properties at room temperature(RT) were investigated.The microstructure shows dendrites with addition of 0 at%-2.5at% Zr,and the dendrites are refined with the primary dendrite arms spacing decreasing from 222.64 μm(0 at%Zr) to 92.57 μm(2.0 at% Zr).With Zr addition more than2.5 at%,the microstructure shows equiaxed grains surrounded by y phase.Zr is a y stabilizer and promotes the β/y transition,resulting in the change of microstructure morphology.Zr reaches the maximum solid solubility(about 6.5 at%) in y phase with addition of 2.5 at% Zr;moreover,γ phase increases in quantity,bringing about severe micro-segregation.With addition of Zr,the remained β phase turns into ω phase with B82 structure.Ti43Al6Nb-xZr alloys show brittle fracture.The maximum compressive strength is 2161.69 MPa with addition of 2.5at% Zr and the maximum compressive strain is 30.62%with addition of 0.5 at% Zr,improving by 9.24% and7.33%,respectively.The improvement of compressive strength results from fine-grain strengthening and solution strengthening.Severe micro-segregation is bad for compressive strength,and large solubility of Zr is detrimental to ductility.

关 键 词：TiAl alloys ZR Microstructure evolution MICRO-SEGREGATION Mechanical properties 

分 类 号：TG146.23[一般工业技术—材料科学与工程]