The dislocation sub-structure evolution during hot compressive deformation of Ti-6Al-2Zr-1Mo-1V alloy at 800 °C

Abstract

Hot compressive behaviors of Ti-6Al-2Zr-1Mo-1V alloy at 800 °C, as well as the evolution of microstructure during deformation process, were investigated. The experimental results show that flow stress increases to a peak stress followed by a decease with increasing strain, and finally forms a stable stage. Dislocations are generated at the interface of α/β phase, and the phase interface and dislocation loops play an important role in impeding the movement of dislocation. As strain increasing, micro-deformation bands with high-density dislocation are formed, and dynamic recrystallizaton occurs finally. XRD Fourier analysis reveals that dislocation density increases followed by a decrease during compressive deformation, and falls into the range from 10¹⁰ to 10¹¹ cm⁻².

Keywords

Ti-6Al-2Zr-1Mo-1V alloy / hot compressive deformation behavior / dislocation sub-structure evolution

References

[1] Gilbert J R B. The Use of Titanium[J]. Materials Science and Technology, 1985, (1): 257–259

[2] Kimura K., Ishii M., Yoshimura H. An Analysis of Deformation, Temperature, and Microstructure for Hot Extruded Titanium Alloy[J]. Metallurgical Transactions B, 1993, 24B: 139-144.

[3] Seshacharyulu T., Medeiros S. C., Frazier W. G., Prasad Y. V. R. K. Microstructural Mechanisms during Hot Working of Commercial Grade Ti-6Al-4V with Lamellar Starting Structure[J]. Materials Science and Engineering A, 2002, 325: 112-125.

[4] Ding R., Guo Z. X., Wilson A. Microstructural Evolution of A Ti-6Al-4V Alloy during Thermomechanical Processing[J]. Materials Science and Engineering A, 2002, 327: 233-245.

[5] Seshacharyulu T., Medeiros S. C., Frazier W. G., . Hot Working of Commercial Ti-6Al-4V with An Equiaxed α-β Microstructure: Materials Modeling Considerations[J]. Materials Science and Engineering A, 2000, 284: 184-194.

[6] Seshacharyulu T., Medeiros S. C., Morgan J. T., . Hot Deformation Mechanisms In ELI Grade Ti-6A1-4V[J]. Scripta Materialia, 1999, 41(3): 283-288.

[7] Seshacharyulu T., Medeiros S. C., Morgan J. T., . Hot Deformation and Microstructural Damage Mechanisms in Extra-low Interstitial (ELI) Grade Ti-6Al-4V[J]. Materials Science and Engineering A, 2000, 279: 289-299.

[8] Semiatin S. L., Thomas J. E., Dadras P. Processing-Microstructure Relationships for Ti-6AI-2Sn-4Zr-2Mo- 0.1Si[J]. Metallurgical Transactions A, 1983, 14: 2363-2374.

[9] Xu W., Shan D., Li C., . Study on the Dynamic Hot Compression Behavior and Deformation Mechanism of TA15 Titanium Alloy[J]. Journal of Aeronautical Materials, 2005, 25(4): 10-15.

[10] Glavicic M. G., Semiatin S. L. X-ray Line-broadening Investigation of Deformation during Hot Rolling of Ti-6Al-4V with a Colony-alpha Microstructure[J]. Acta Materialia, 2006, 54: 5337-5347.

[11] Chen W., Gao Z., Huang Jiaju. A Study on Dislocation Density and Dislocation Configuration in 20CrMnTi steel[J]. Journal of Jilin University(Engineering and Technology Edition), 2004, 34(1): 31-34.

[12] Wang Rizhi. Hot Deformation and Dynamic Restoration of Low Carbon Steels in (F+A) Two-Phase Range[D], 1993 Harbin Harbin Institute of Technology