Study the phase transformation of Ti-6242 alloy and Determination the beta-transus temperature
Subject Areas :علیرضا حجاری 1 , مریم مرکباتی 2 , رامین حسینی 3 , یاور منصوری 4 , مهدی عباسی 5
1 - دانشگاه صنعتی مالک اشتر تهران
2 - هیات علمی دانشگاه صنعتی مالک اشتر تهران
3 - دانشگاه صنعتی مالک اشتر تهران
4 - دانشگاه صنعتی مالک اشتر تهران
5 - هیات علمی دانشگاه صنعتی مالک اشتر تهران
Keywords: Ti-6242 alloy, beta transus temperature, alpha and beta phases, Hot torsion,
Abstract :
The aim of this research is to determine the beta transus temperature of two Ti-6242 alloys and to study the effect of different amount of alloying elements on alpha and beta phase stabilization by microstructural observation and hot torsion test. Determination of beta transus temperature has an important influence on designing thermomechanical and heat treatment cycles of titanium alloys. Hence, this is an effective parameter to control mechanical properties of two phase titanium alloys. In this regard, hot torsion tests were performed at temperature range of 960 °C to 1090 °C using the strain rate of 0.001 s-1 by cooling with the rate of 0.5 °C/s. besides, in order to deduce the temperature of grain boundary alpha phase nucleation and microstructural evolution, the specimens were heat treated at temperature range of 980 °C to 1020 °C for 40 minute and water quenched. It was found that, 10 % increase in Aleq/Moeq ratio, makes a 5 °C increase in beta transus temperature of the Ti-6242 alloy. Accordingly, this temperature was estimated in the temperature range of 1000 °C to 1010 °C for these alloys. Furthermore, there is a 10 °C deviation in the hot torsion test results and microstructural analysis, which is attributed to dynamic strain-induced transformation phenomenon.
[1] G. Welsch, R. Boyer & E. W. Collings, “Materials Properties Handbook: Titanium Alloys”, ASM International, 1993.
[2] G. Lütjering and J. C. Williams, “Titanium”, Springer, 2007.
[3] Z. Guo, S. Malinov & W. Sha, “Modelling beta transus temperature of titanium alloys using artificial neural network”, Computational materials science, Vol. 32, pp. 1-12, 2005.
[4] Polmear, “Light Alloys: From Traditional Alloys to Nanocrystals”, fourth ed.: Elsevier Science, 2005.
[5] C. Leyens & M. Peters, “Titanium and Titanium Alloys: Fundamentals and Applications”, Wiley, 2006.
[6] V. N. Moiseyev, “Titanium Alloys: Russian Aircraft and Aerospace Applications”, Taylor & Francis, 2005.
[7] W. Sha & Z. Guo, “Phase evolution of Ti–6Al–4V during continuous heating”, Journal of Alloys and Compounds, Vol. 290L, pp. 3-7, 1999.
[8] S. Tamirisakandala, R. B. Bhat, D. B. Miracle, S. Boddapati, R. Bordia & R. Vanover, et al., “Effect of boron on the beta transus of Ti–6Al–4V alloy”, Scripta Materialia, Vol. 53, pp. 217-222, 2005.
[9] S. Roy, V. Tungala & S. Suwas, “Effect of Hypoeutectic Boron Addition on the β Transus of Ti-6Al-4V Alloy”, Metallurgical and Materials Transactions, Vol. 42A, pp. 2535-2541, 2011.
[10] P. Tarín, M. C. Rodríguez, A. G. Simón, N. M. Piris, J. M. Badía & J. M. Antoranz, “α ↔ β changes in Ti-6A1-2Sn-4Zr-2Mo-Si alloy: Characterization, microstructure, and mechanical properties”, Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, Vol. 220, pp. 241-246, 2006.
[11] N. Saunders, X. Li, A. Miodownik & J. Schille, “An Integrated Approach To The Calculation Of Materials Properties For Ti-Alloys”, in Proceedings of the 10th World Conference on Titanium. Hamburg, 2005.
[12] M. Rakhshkhorshid, S. H. Hashemi & H. Monajatizadeh, “The use of hot torsion testing for determination of critical temperatures of API X65 steel”, Modares Mechanical Engineering, Vol. 14, 2015.
[13] T. Ahmed & H. J. Rack, “Phase transformations during cooling in α+β titanium alloys”, Materials Science and Engineering, Vol. 243A, pp. 206-211, 1998.
[14] Kumar, T. Jayakumar, B. Raj & D. Banerjee, “A new methodology for identification of β-transus temperature in α+ β and β titanium alloys using ultrasonic velocity measurement”, Philosophical Magazine, Vol. 88, pp. 327-338, 2008.
[15] F. Zhang, F.-Y. Xie, S.-L. Chen, Y. Chang, D. Furrer & V. Venkatesh, “Predictions of titanium alloy properties using thermodynamic modeling tools”, Journal of materials engineering and performance, Vol. 14, pp. 717-721, 2005.
[16] N. Reddy, C. Lee, J. Kim & S. Semiatin, “Determination of the beta-approach curve and beta-transus temperature for titanium alloys using sensitivity analysis of a trained neural network”, Materials Science and Engineering, Vol. 434A, pp. 218-226, 2006.
[17] P. Hodgson, D. Collinson & B. Perrett, “The use of hot torsion to simulate the thermomechanical processing of steel”, Physical Simulation of Casting, Hot Rolling and Welding, pp. 219-229, 1997.
[18] H. Beladi, G. Kelly, A. Shokouhi & P. Hodgson, “Effect of thermomechanical parameters on the critical strain for ultrafine ferrite formation through hot torsion testing”, Materials Science and Engineering, Vol. 367A, pp. 152-161, 2004.
[19] Shokouhi & P. Hodgson, “Dynamic adjustment of ferrite grains during dynamic strain induced transformation”, Materials science and technology, Vol. 23, pp. 1233-1242, 2007.
[20] Shokouhi & P. Hodgson, “Effect of transformation mechanism (static or dynamic) on final ferrite grain size”, Materials science and technology, Vol. 25, pp. 29-34, 2009.
[21] G. E. Dieter, H. A. Kuhn & S. L. Semiatin, “Handbook of Workability and Process Design”, ASM International, 2003.
[22] J. S. Fields & W. A. Backofen, “Determination of strain-hardening characteristics by torsion testing”, american society for testing and materials proceedings, Vol. 57, pp. 1259-1272, 1957.
[23] Weiss and S. L. Semiatin, “Thermomechanical processing of alpha titanium alloys an overview”, Materials Science and Engineering: A, vol. 263, pp. 243-256, 1999.
[24] Weiss & S. L. Semiatin, “Thermomechanical processing of beta titanium alloys an overview”, Materials Science and Engineering, Vol. 243A, pp. 46-65, 1998.
[25] S. L. Semiatin & T. R. Bieler, “The effect of alpha platelet thickness on plastic flow during hot working of TI–6Al–4V with a transformed microstructure”, Acta Materialia, Vol. 49, pp. 3565-3573, 2001.
[26] P. Dadras & J. F. Thomas, “Characterization and modeling for forging deformation of Ti-6Ai-2Sn-4Zr-2Mo-0.1 Si”, Metallurgical Transactions, Vol. 12A, pp. 1867-1876, 1981.
[27] Y. V. R. K. Prasad & S. Sasidhara, “Hot Working Guide: A Compendium of Processing Maps”, ASM International, 1997.
[28] R. Abbaschian & R. Reed-Hill, “Physical Metallurgy Principles - SI Version”, Cengage Learning, 2009.
[29] R. E. Smallman & A. H. W. Ngan, “Physical Metallurgy and Advanced Materials”, Elsevier Science, 2011.
[30] Dehghan-Manshadi & R. J. Dippenaar, “Strain-induced phase transformation during thermo-mechanical processing of titanium alloys”, Materials Science and Engineering, Vol. 552A, pp. 451-456, 2012.
[31] Liu, H. Matsumoto, Y. P. Li, Y. Koizumi, Y. Liu, & A. Chiba, “Dynamic Phase Transformation during hot-forging process of a powder metallurgy alpha+beta; Titanium Alloy”, Materials Transactions, Vol. 53, pp. 1007-1010, 2012.
