Fine Grain Formation in as Cold Worked SP700 Titanium Alloy and Its Effect on Mechanical and Superplastic Properties
محورهای موضوعی : Thermomechanical
Marjan Daryaban
1
(MS. C., Department of Materials and Manufacturing Thechnologies, Malek Ashtar University of Technology, Tehran, Iran.)
Maryam Morakabati
2
(Associate Professor, Department of Materials and Manufacturing Thechnologies, Malek Ashtar University of Technology, Tehran, Iran.)
Noshin Meraji
3
(MS. C., Department of Materials and Manufacturing Thechnologies, Malek Ashtar University of Technology, Tehran, Iran)
کلید واژه: SP700 titanium alloy, Cold working, Dynamic recrystallization, Superplastic, Fundamental equations,
چکیده مقاله :
The aim of this research is to study the effect of fine grain structure on the mechanical and superplastic properties of cold worked SP700 alloy. Thickness reductions of 20%, 40%, and 60%. were applied during cold rolling. Then the specimens were annealed at 700°C, 750°C, and 800°C for 40 minutes. The tensile test was applied at 25, 700oC, 750°C, and 800°C with strain rates of 0.01s-1, 0.005s-1 and 0.001s-1. The SEM and OM were used to analyze the specimens' microstructures. The alloy cold rolled to 40% reduction and annealed at 700°C exhibited a maximum elongation of 1380% at a stress level of 30 MPa and a strain rate of 0.005 s-1 at 700°C. Microstructural evlauation showed that during the superplastic test, dynamic recrystallization took place. The strain rate sensitivity varied in the range of 0.32 to 0.46. Fundamental equations were also used to determine the mechanism of superplasticity. The activation energy is obtained as 385 kJ.mol-1. Results validated that the Rachinger sliding is the main superplastic mechanism in the SP700 alloy.
The aim of this research is to study the effect of fine grain structure on the mechanical and superplastic properties of cold worked SP700 alloy. Thickness reductions of 20%, 40%, and 60%. were applied during cold rolling. Then the specimens were annealed at 700°C, 750°C, and 800°C for 40 minutes. The tensile test was applied at 25, 700oC, 750°C, and 800°C with strain rates of 0.01s-1, 0.005s-1 and 0.001s-1. The SEM and OM were used to analyze the specimens' microstructures. The alloy cold rolled to 40% reduction and annealed at 700°C exhibited a maximum elongation of 1380% at a stress level of 30 MPa and a strain rate of 0.005 s-1 at 700°C. Microstructural evlauation showed that during the superplastic test, dynamic recrystallization took place. The strain rate sensitivity varied in the range of 0.32 to 0.46. Fundamental equations were also used to determine the mechanism of superplasticity. The activation energy is obtained as 385 kJ.mol-1. Results validated that the Rachinger sliding is the main superplastic mechanism in the SP700 alloy.
[1] Q. Qiu, K. Wang, X. Li, J. Wang, X. Gao, K. Zhang, "Hot deformation behavior and processing parameters optimization of SP700 titanium alloy," J. Mate. Resea. Tech., Vol. 15, 2021, pp. 3078-3087.
[2] R. Boyer, G. Welsch, E.W. Collings, Materials Properties Handbook: Titanium Alloys, United States: ASM International, 1994, p. 246.
[3] E. Alabort, D. Barba, M.R. Shagiev, M,A. Murzinova, R.M. Galeyev, O.R. Valiakhmetov, A.F. Aletdinov, R.C. Reed, "Alloys-by-design: Application to titanium alloys for optimal superplasticity," Acta Mater., vol. 178, 2019, pp. 275-287.
[4] E. Alabort, D. Putman, R.C. Reed, "Superplasticity in Ti-6Al-4V: Characterisation, modeling and applications," Acta Mate., vol. 95, 2015, pp. 428-442.
[5] J. L. T. D. D. B. T. G. Z. Z. Q. Bai, "Modelling of dominant softening mechanisms for Ti-6Al-4V in steady state hot forming conditions," Mat. Sci. and Eng. A, Vol. 559, 2013, pp. 352-358.
[6] J. Luo, L.F. Wang, S.F. Liu, M.Q. Li, "The correlation between the flow behavior and the microstructure evolution during hot working of TC18 alloy," Mat. Sci. and Eng. A, Vol. 654, 2016, pp. 213–220.
[7] E. Alabort, P. Kontis, D. Barba, K. Dragnevski, R.C. Reed, "On the mechanisms of superplasticity in Ti-6Al-4V," Acta Mat., Vol. 105, 2016, pp. 449-463.
[8] S. H. Hsiang Lina, "Microtwin formation in the alpha phase of duplex titanium alloys affected by strain rate," Mat. Sci. and Eng. A, Vol. 528, 2011, pp. 2271-2276.
[9] Y. Zhang, Sh. Chang, Y. Chen, Y. Bai, C. Zhao, X. Wang, J. M. Xue, H. Wang, "Low-temperature superplasticity of β-stabilized Ti-43Al-9V-Y alloy sheet with bimodal γ-grain-size distribution," J. . Sci. Tech., Vol. 95, 2021, p. 225–236.
[10] J. Shen, Y. Sun, Y. Ning, H. Yu, Z. Yao, L. Hu, "Superplasticity induced by the competitive DRX between BCC beta and HCP alpha in Ti-4Al-3V-2Mo-2Fe alloy," Mate. Charac., Vol. 153, 2019, pp. 304–317.
[11] AMS 4899C, "Titanium Alloy, Sheet, Strip, and Plate Ti-4.5Al-3V-2Fe-2Mo Annealed," 2011.
[12] AMS 4964C, "Titanium Alloy Bars, Wire, Forgings, and Rings Ti-4.5Al-3V-2Fe-2Mo Annealed," 2011.
[13] ASTM E8/E8M-13, Standard Test Methods for Tension Testing of Metallic Materials, West Conshohocken: ASTM International, 2013.
[14] F. a. M.Hatherly, Recrystallization and Related Annealing Phenomena, Elsevier, 2004. p. 245.
[15] Y. W. S. X. H. S. Tian N, " Microstructure and Texture Evolution during Superplastic Deformation of SP700 Titanium Alloy," Mater., Vol. 15, No. 5, 2022, 1808.
[16] Z. W. M. L. Z. P. H. B. Piao R, "Characterization of Hot Deformation of near Alpha Titanium Alloy Prepared by TiH2-Based Powder Metallurgy," Mater., Vol. 15, No. 17, 2022, 5932.
[17] . Zener, J.H. Hollomon, "Effect of Strain Rate Upon Plastic Flow of Steel," J. Appl. Phy., Vol. 15, 1994, pp. 22-32.
[18] K.A. Padmanabhan, R.A. Vasin, F.U. Enikeev, "Superplastic Flow, Phenomenology and Mechanics", Springer-Verlag Berlin Heidelberg, New York, 2001.
[19] M.J.Tan, G.W.Chen, S.Thiruvarudchelvan, "High temperature deformation in Ti–5Al–2.5Sn alloy," J. Mater. Proc. Tech., Vol. 192-193, 2007, pp. 434-438.
[20] M. Meier, D. Lesuer, A. Mukherjee, "The effects of the α/β phase proportion on the superplasticity of Ti-6Al-4V and iron-modified Ti-6Al-4V," Mat. Sci. and Eng. A, Vol. 154, 1992, pp. 165-173.
[21] I. Balasundar, T. Raghua, P. Kashyap, "Modeling the hot working behavior of near-α titanium alloy IMI 834," Progress in Natural Science: Materials International, Vol. 23, 2013, pp. 598-607.
[22] P. Wanjara, M. Jahazi, H. Monajati, S. Yue, J.P. Immarigeon, "Hot working behavior of near-α alloy IMI834," Mat. Sci. and Eng. A, Vol. 396, 2005, pp. 50-60.
[23] Z. Ma, R. Mishra, Friction Stir Superplasticity for Unitized Structures, Butterworth-Heinemann, 2014, p. 39-57.
[24] Q. Yang, K. Qiu, R. Jiang, D. Huang, "Characterization of Hot Deformation Behavior of TC18 Titanium Alloy," Mat. Sci. For., Vol. 815, 2015, pp. 263-267.
[25] L.W. Zhu, X.N. Wang, Y. Fei, J. Li, Z.Sh. Zhu, "Characterization of hot deformation behavior of Ti-4.5Al-3V-2Mo-2Fe titanium alloy," Mat. Sci. For., Vol. 849, 2016, pp. 309-316.
[26] A. H. Sheikhali, M. Morakabati, S. M. Abbasi, "Hot torsion behavior of SP-700 near beta titanium alloy in single and dual phase regions" Inte. J..Mate. Resea., Vol. 109, no. 12, 2018, pp. 1136-1145.
[27] M. J. Tan, G.W. Chen, S. Thiruvarudchelvan "High temperature deformation in Ti–5Al–2.5Sn alloy," J. Mat. Proc. Tech., Vols. 192-193, 2007, pp. 434-438.
[28] V.G. Krishna, Y.V.R.K. Prasad, N.C. Birla, G.S. Rao, "Processing map for the hot working of near-α titanium alloy 685," J. Mat. Proc. Tech., Vol. 71, 1997, pp. 377-383.
