Abstract
Isothermal torsion tests were performed on a Ti–6Al–4V alloy in the two-phase region. The results show that straining leads to an increase in the beta phase fraction, which increases slightly with strain rate. Transformation took place at 880, 940, 960, 980 and 1000 °C. The extent of this type of dynamic transformation (alpha to beta) was increased when the temperature approached the transus temperature. The reverse transformation (beta to alpha) occurred during isothermal holding after torsion and the volume fraction retransformed increased with time. The driving forces promoting dynamic and reverse transformation together with the energy barriers opposing these transformations were derived and compared. The critical stresses required to initiate dynamic transformation are calculated from the flow curves. This analysis confirms that the peak stresses are always higher than the critical stresses at the temperatures employed in the present tests, which makes it possible for the transformation to occur.
Similar content being viewed by others
References
Senuma T (1986) Massive type transformation induced by hot deformation in low carbon steels. In: Proceedings of international conference on martensitic transformations, Nara, pp 515–520
Yada H, Li C-M, Yamagata H (2000) Dynamic γ → α transformation during hot deformation in iron–nickel–carbon alloys. ISIJ Int 40:200–206
Ying C, Qi-an C (2003) Dilatometric investigation on isothermal transformation after hot deformation. J Iron Steel Res Int 10:46–48
Sun X, Luo H, Dong H, Liu Q, Weng Y (2008) Microstructural evolution and kinetics for post-dynamic transformation in a plain low carbon steel. ISIJ Int 48:994–1000
Aranas C Jr., Nguyen-Minh T, Grewal R, Jonas JJ (2015) Flow softening-based formation of Widmanstätten ferrite in a 0.06% C steel deformed above the Ae3. ISIJ Int 55:300–307
Aranas C, Rodrigues SF, Shen YJ, Zhang Z, Jonas JJ (2017) Time-temperature-reverse transformation (TTRT) behaviors of a C‐Mn and a Nb microalloyed steel after dynamic transformation above the Ae3. Steel Res Int 88:1–7
Ghosh C, Basabe VV, Jonas JJ, Kim Y-M, Jung I-H, Yue S (2013) The dynamic transformation of deformed austenite at temperatures above the Ae3. Acta Mater 61:2348–2362
Xiao N, Tong M, Lan Y, Li D, Li Y (2006) Coupled simulation of the influence of austenite deformation on the subsequent isothermal austenite–ferrite transformation. Acta Mater 54:1265–1278
Ghosh C, Basabe VV, Jonas JJ (2014) Thermodynamics of dynamic transformation of hot deformed austenite in four steels of increasing carbon contents. Mater Sci Eng A 591:173–182
Jonas JJ, Ghosh C (2013) Role of mechanical activation in the dynamic transformation of austenite. Acta Mater 61:6125–6131
Aranas C, Jonas JJ (2015) Effect of Mn and Si on the dynamic transformation of austenite above the Ae3 temperature. Acta Mater 82:1–10
Ghosh C, Aranas C, Jonas JJ (2016) Dynamic transformation of deformed austenite at temperatures above the Ae3. Prog Mater Sci 82:151–233
Ghosh C, Basabe VV, Jonas JJ, Yue S, Xiong XY (2013) Dynamic transformation behavior of a deformed high carbon steel at temperatures above the Ae3. ISIJ Int 53:900–908
Koike J, Shimoyama Y, Ohnuma I, Okamura T, Kainuma R, Ishida K, Maruyama K (2000) Stress-induced phase transformation during superplastic deformation in two-phase Ti–Al–Fe alloy. Acta Mater 48:2059–2069
Yang H, Gurewitz G, Mukherjee A (1991) Mechanical behavior and microstructural evolution during superplastic deformation of Ti–6Al–4V. Mater Trans JIM 32:465–472
Prada BH, Mukhopadhyay J, Mukherjee AK (1990) Effect of strain and temperature in a superplastic Ni-modified Ti–6Al–4V Alloy. Mater Trans JIM 31:200–206
Lu C, Huang L, Geng L, Kaveendran B, Zheng Z, Zhang J (2015) Mechanisms behind the superplastic behavior of as-extruded TiBw/Ti6Al4V composites with a network architecture. Mater Charact 104:139–148
Matsumoto H, Yoshida K, Lee S-H, Ono Y, Chiba A (2013) Ti–6Al–4V alloy with an ultrafine-grained microstructure exhibiting low-temperature–high-strain-rate superplasticity. Mater Lett 98:209–212
Zhang T, Liu Y, Sanders DG, Liu B, Zhang W, Zhou C (2014) Development of fine-grain size titanium 6Al–4V alloy sheet material for low temperature superplastic forming. Mater Sci Eng A 608:265–272
Ding R, Guo Z, Wilson A (2002) Microstructural evolution of a Ti–6Al–4V alloy during thermomechanical processing. Mater Sci Eng A 327:233–245
Zong Y, Shan D, Xu M, Lv Y (2009) Flow softening and microstructural evolution of TC11 titanium alloy during hot deformation. J Mater Process Technol 209:1988–1994
Jonas JJ, Aranas C, Fall A, Jahazi M (2016) Transformation softening in three titanium alloys. Mater Des 113:305–310
Fields D, Backofen W (1957) Determination of strain hardening characteristics by torsion testing. Proc ASTM 57:1259–1272
Jonas JJ, Ghosh C, Quelennec X, Basabe VV (2013) The critical strain for dynamic transformation in hot deformed austenite. ISIJ Int 53:145–151
Goetz R, Semiatin SL (2001) The adiabatic correction factor for deformation heating during the uniaxial compression test. J Mater Eng Perform 10:710–717
Senkov O, Jonas JJ (1996) Effect of phase composition and hydrogen level on the deformation behavior of titanium-hydrogen alloys. Metall Mater Trans A 27:1869–1876
Rack HJ, Qazi J, Allard L, Valiev R (2008) Thermal stability of severe plastically deformed VT-6 (Ti–6Al–4V). In: Materials Science Forum, Trans Tech Publ, pp 893–898
Sargent GA, Kinsel KT, Pilchak AL, Salem AA, Semiatin SL (2012) Variant selection during cooling after beta annealing of Ti–6Al–4V ingot material. Metall Mater Trans A 43:3570–3585
Ohmori Y, Nakai K, Ohtsubo H, Tsunofuri M (1994) Formation of Widmanstätten alpha structure in a Ti–6Al–4V alloy. Mater Trans JIM 35:238–246
Semiatin SL, Zhang F, Larsen R, Chapman L, Furrer D (2016) Precipitation in powder-metallurgy, nickel-base superalloys: review of modeling approach and formulation of engineering methods to determine input data. IMMI 5:3–20
Semiatin SL, Kirby B, Salishchev G (2004) Coarsening behavior of an alpha-beta titanium alloy. Metall Mater Trans A 35:2809–2819
Semiatin SL, Brown T, Goff T, Fagin P, Turner R, Murry J, Barker D, Miller J, Zhang F (2004) Diffusion coefficients for modeling the heat treatment of Ti–6Al–4V. Metall Mater Trans A 35:3015–3018
Aranas C, Foul A, Guo B, Fall A, Jahazi M, Jonas JJ (2017) Determination of the critical stress for the initiation of dynamic transformation in commercially pure titanium. Scr Mater 133:83–85
Guo B, Aranas C, Sun B, Ji X, Jonas JJ (2017) Reverse transformation behavior of Ti–6Al–4V after deformation in the two-phase region. Metall Mater Trans A 49:22–27
Acknowledgements
The authors are grateful to Dr. Clodualdo Aranas Jr. of CanmetMATERIALS and Prof. Mohammad Jahazi and Dr. Ameth Fall of Ecole de Technologie Superieure (ETS) for discussions. The authors acknowledge with gratitude funding received from the China Scholarship Council and the McGill Engineering Doctoral Award program.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflicts of interest.
Rights and permissions
About this article
Cite this article
Guo, B., Semiatin, S.L., Jonas, J.J. et al. Dynamic transformation of Ti–6Al–4V during torsion in the two-phase region. J Mater Sci 53, 9305–9315 (2018). https://doi.org/10.1007/s10853-018-2237-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10853-018-2237-0