Superplasticity of a Ti-48Al-2.3Cr-0.2Mo Alloy
Superplastic behaviors of a Ti-48A1-2.3Cr-0.2Mo alloy with the initial grain size of 0.6μm,resulting from 3-steps forging,have been investigated at temperatures ranging from 950℃ to 1100℃ and at strain rates ranging from 8×10-5 s-1 to 2×10-4s-1.The elongations above 500% were obtained at 1050℃-1100℃.An maximum elongation of 566% was obtained at 1050℃and at a strain rate of 8×10-5s-1.The flow softening and continuous strain hardening were observed in the curves of true stress-true strain,it is suggested dynamic recrystallization and high-density dislocation caused by pre-deformation are the reasons.By OA,TEM,microstructure evolutions during the deformation were observed.It is found that after superplastic deformation,the grain size become smaller,and the distribution of grain size become more uniform,the densities of dislocations become lower and the dislocations mainly distributed in the areas near grain triple junction.Grain boundary sliding accommodated by dislocation slip is the predominant deformation mechanism.
Superplasticity TiAl alloy Dynamic Recrystallization
Zhang Junhong Xu Guohui Xu Yajuan He Yuehui
Department of Materials Science and Engineering, Luoyang Institute Science and Technology,Luoyang, 4 State Key Laboratory for Powder Metallurgy, Central South University, Changsha, 410083, China
国际会议
广州
英文
27-31
2012-11-16（万方平台首次上网日期，不代表论文的发表时间）