Influence of Rare Earth Y on the High Temperature Deformability of TiAl Alloys
The effects of yttrium additions on plastic deformability and the change of microstructures after deformation of TiAl alloys were investigated by isothermal hot-compression pressing. The experiments were conducted with the Gleeble-1500D style of thermo-force analogue machine. The results indicated that the higher the deformation temperature and the lower the strain rate, the smaller the deformation resistance, and adding 0.3at.％Y can improve remarkably hot deformability of Ti-43Al-9V and Ti-45Al-5Nb alloys at the same processing parameters. Comparing with the microstructures of Y-free TiAl alloys after deformation, the grains sizes of Y containing TiAl alloys were much finer and the fraction of the fine equiaxed γ grains formed by dynamic recrystallization increased, and the addition of 0.3at.％Y decreased the flow stress and the deformation activation energy of Ti-43Al-9V and Ti-45Al-5Nb alloys. According to the isothermal hot-compression pressing results, appropriate sets of deformation processing parameters are recommended for the present Y containing TiAl alloys. These recommended hot deformation processing parameters have been successfully used for the quasi-isothermal canned forging of 0.3％Y containing TiAl alloy billets.
TiAl alloy Rare earths Deformation Microstructure Hot-compression
Fantao KONG Yuyong CHEN Baohui Li
School of materials science and engineering, Harbin institute of technology p.o.box 434 Harbin 150001 P.R.China
国际会议
郑州
英文
2007-10-23（万方平台首次上网日期，不代表论文的发表时间）