Microstructure Evolution of Rapidly Solidified TiAl Alloys with Various Nb Contents
TiAl alloy is a kind of attractive high temperature structural materials because of the low density,high strength,and good creep resistance and good oxidization resistance. However,the low ductility was the main obstacle for their extensive application. Rapid solidification technique is a method to solve this problem by refining and homogenizing the microstructure. The alloy ribbons with nominal composition of Ti-46Al-(2,4,6) Nb-(Cr,Y)(at. ％) were used in this work,which were prepared by meltspinning method. The results show that higher Nb content decreases both the thickness and width of ribbons. All the free surfaces exhibit dendrite structure with the secondary dendrite arms oriented 60 degree to the primary dendrite spines. Increasing Nb addition leads to a more flat free surface. The three alloys are composed of α+γ phases,and Nb addition does not alter the phase constitutions. The microstructure of the near roller contacted surface of the three alloys is composed of equiaxed grain and lamellar structure or massively transformed γm grain. The volume fraction of massively transformed γm grain increases with raising Nb content.
TiAl rapid solidification microstructure Nb
Lihua Chai Yuyong Chen Junpin Lin
State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing, School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 ,China
国际会议
The 12th World Conference Titanium(第十二届世界钛会 Ti-2011)
北京
英文
1379-1382
2011-06-19（万方平台首次上网日期，不代表论文的发表时间）