Effects of Annealing on Microstructure and Microhardness of TA15 Titanium Alloy Processed by Equal Channel Angular Pressing

Abstract:

The primary purpose of the present work is to investigate the effects of annealing after equal channel angular pressing (ECAP) on microstructure and microhardness of TA15 titanium alloy. A study was performed by annealing treatment on the microstructure evolution and microhardness variation of ECAPed TA15 alloy. The results state that, static recrystallization occurred distinctly during annealing after ECAP. Since a sample was annealed at a proper temperature and for proper time after ECAP, a larger amount of well globularized and more homogeneous equiaxed α phase has been attained, grains have not grown observably, and the relief of residual stress and work hardening for subsequent processing and using has also been achieved. Accordingly, the optimum annealing parameters of ECAPed TA15 alloy were optimized to be 973 K and 1 hour. The microhardness level of the sample annealed after ECAP was lower than that unannealed, and the microhardness level decreased with the increasing annealing temperature and time.

• Periodical: Materials Science Forum (Volumes 675-677)
• Pages: 735-738
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.675-677.735
• Online since: February 2011
• Authors: Yan Zhao, Hong Zhen Guo, Zhi Feng Shi, Yong Qiang Zhang, Ze Kun Yao, Li Jun Tan, Tao Wang
• Keywords: Annealing, Equal-Channel Angular Pressing (ECAP), Microhardness, Microstructure, TA15 Titanium Alloy

References

[1] X.W. Li, A.X. Sha and W.F. Zhang: (In Chinese) Titanium Industry Progress Vol. 20 (2003), p.90.

[2] R.Z. Valiev and T. G. Langdon: Prog. Mater. Sci. Vol. 51 (2006), p.881.

[3] F.J. Humphreys and M. Hatherly, in: Recrystallization and Related Annealing Phenomenon, Elsevier Publishers, (2004).

[4] S.L. Kakani and A. Kakani, in: Material Science, New Age Publishers, (2004).

[5] S.C. Yuan: (In Chinese) Processing parameters and mechanism of ECAP of Ti-1023 alloy (Northwestern Polytechnical University, China 2008).

[6] S.Y. Wei and Y. He: (In Chinese) Titanium Industry Progress Vol. 3 (2000), p.11.