Coupled Influence of Temperature and Strain Rate on Tensile Deformation Characteristics of Hot-Extruded AZ31 Magnesium Alloy

doi:10.1007/s40195-016-0373-6

Abstract

Abstract:

To explore the coupled effect of temperature T and strain rate ε˙ε˙ on the deformation features of AZ31 Mg alloy, mechanical behaviors and microstructural evolutions as well as surface deformation and damage features were systematically examined under uniaxial tension at T spanning from 298 to 523 K and ε˙ε˙ from 10^-4 to 10^-2 s^-1. The increase in T or the decrease in ε˙ε˙ leads to the marked decrease in flow stress, the appearance of a stress quasi-plateau after an initially rapid strain hardening, and even to the occurrence of successive strain softening. Correspondingly, the plastic deformation modes of AZ31 Mg alloy transform from the predominant twinning and a limited amount of dislocation slip into the enhanced non-basal slip and the dynamic recrystallization (DRX) together with the weakened twinning. Meanwhile, the cracking modes also change from along grain boundaries (GBs) and at twin boundaries (TBs) or the end of twins into nearby GBs where the DRX has occurred. The appearance of a stress quasi-plateau, the formation of large-sized cracks nearby GBs, and the occurrence of continuous strain softening, are intimately related to the enhancement of the non-basal slip and the DRX.

Key words: AZ31, Mg, alloy, Uniaxial, tension, Temperature, Strain, rate, Deformation, Damage, Twinning

Ying Yan, Wan-Peng Deng, Zhan-Feng Gao, Jing Zhu, Zhong-Jun Wang, Xiao-Wu Li. Coupled Influence of Temperature and Strain Rate on Tensile Deformation Characteristics of Hot-Extruded AZ31 Magnesium Alloy[J]. Acta Metallurgica Sinica (English Letters), 2016, 29(2): 163-172.

Figures/Tables 10

Fig. 1 OM image of microstructure of as-extruded AZ31 Mg alloy

Fig. 2 Tensile true stress-strain curves of AZ31 Mg alloy at various temperatures, respectively, at the strain rates ofa 10-4 s-1, b 10-3 s-1, c 10-2 s-1

Fig. 3 Tensile true stress-strain curves of AZ31 Mg alloy at different strain rates and different temperatures: a 298 K and 373 K; b 423 K; c 473 K; d 523 K

Fig. 4 Variations of ultimate tensile strength σUTS and yield strength σ YS of AZ31 Mg alloy with temperature at different strain rates

Fig. 5 Low-magnification SEM images of the surface deformation features for AZ31 Mg alloy deformed at different temperatures and strain rates: a 298 K, 10-4 s-1; b 298 K, 10-2 s-1; c 373 K, 10-4 s-1; d 373 K, 10-2 s-1; e 423 K, 10-4 s-1; f 423 K, 10-2 s-1; g 473 K, 10-4 s-1; h 473 K, 10-2 s-1

Fig. 6 High-magnification SEM images of the surface deformation features for AZ31 Mg alloy deformed at different temperatures and strain rates: a 298 K, 10-4 s-1; b 298 K, 10-2 s-1; c 373 K, 10-4 s-1; d 373 K, 10-2 s-1; e 423 K, 10-4 s-1; f 423 K, 10-2 s-1; g 473 K, 10-4 s-1; h 473 K, 10-2 s-1

Fig. 7 OM images of microstructures for AZ31 Mg alloy tensioned at different temperatures and strain rates: a298 K, 10-4 s-1; b 298 K, 10-3 s-1; c 298 K, 10-2 s-1; d 373 K, 10-4 s-1; e 373 K, 10-3 s-1; f 373 K, 10-2 s-1; g 423 K, 10-4 s-1; h 423 K, 10-3 s-1; i 423 K, 10-2 s-1

Fig. 8 OM images of microstructures for AZ31 Mg alloy tensioned at different temperatures and strain rates: a473 K, 10-4 s-1; b 473 K, 10-3 s-1; c 473 K, 10-2 s-1; d 523 K, 10-4 s-1; e 523 K, 10-2 s-1

Fig. 9 TEM images of microstructures for AZ31 Mg alloy at different states: a as-hot-extruded; b deformed at 298 K and 10-2 s-1; c deformed at 423 K and 10-2 s-1; d deformed at 523 K and 10-2 s-1

Fig. 10 Schematics of the major differences in the deformation and damage features and microstructures on the lateral surfaces near fractures after AZ31 Mg alloy was loaded to tensile rupture at low (10-4 s-1) and high (10-2 s-1) strain rates at different temperatures: a 373 K, 10-4 s-1; b 373 K, 10-2 s-1; c 423 K, 10-4 s-1;d 423 K, 10-2 s-1; e 473 K, 10-4 s-1; f 473 K, 10-2 s-1

References 36

[1]	B.L. Mordike, T. Ebert, Mater. Sci. Eng. A 302, 37 (2001)
[2]	F. Li, X. Zeng, N. Bian, Mater. Lett. 135, 79(2014)
[3]	H. Zhang, Y. Yan, J.F. Fan, W.L. Cheng, H.J. Roven, B.S. Xu,H.B. Dong, Mater. Sci. Eng. A 618, 540 (2014)
[4]	H. Zhang, G.S. Huang, J.H. Li, L.F. Wang, H.J. Roven, J. Alloys Compd. 563, 150(2013)
[5]	X. Shang, J. Zhou, X. Wang, Y. Luo, J. Alloys Compd. 629, 155(2015)
[6]	J. Deng, Y.C. Lin, S.S. Li, J. Chen, Y. Ding, Mater. Des. 49, 209(2013)
[7]	E. Karimi, A. Zarei-Hanzaki, M.H. Pishbin, H.R. Abedi, P.Changizian, Mater. Des. 49, 173(2013)
[8]	G. Bajargan, G. Singh, D. Sivakumar, U. Ramamurty, Mater.Sci. Eng. A 579, 26 (2013)
[9]	Y. Koh, D. Kim, D.Y. Seok, J. Bak, S.W. Kim, Y.S. Lee, K.Chung, Inter. J. Mech. Sci. 93, 204(2015)
[10]	J.W. Liu, Z.H. Chen, D. Chen, G.F. Li, Trans. Nonferrous Met.Soc. China 22, 1329 (2012)
[11]	F. Berge, L. Kru¨ger, H. Ouaziz, C. Ullrich, Trans. NonferrousMet. Soc. China 25, 1 (2015)
[12]	I. Ulacia, N.V. Dudamell, F. Ga´lvez, S. Yi, M.T. Acta Mater. 58, 2988(2010)
[13]	T. Al-Samman, Acta Mater. 57, 2229(2009)
[14]	S.R. Agnew, O ¨ . Int. J. Plast. 21, 1161(2005)
[15]	N.V. Dudamell, I. Ulacia, F. Ga´lvez, S. Yi, J. Bohlen, D. Letzig,I. Hurtado, M.T. Mater. Sci. Eng. A 532, 528 (2012)
[16]	D. Ponge, G. Gottstein, Acta Mater. 46, 69(1998)
[17]	G.Y. Cai, X.T. Huang, S.M. Qu, Phys. Proced. 50, 61(2013)
[18]	S. Spigarelli, O.A. Ruano, M. EI Mehtedi, J.A. Mater.Sci. Eng. A 570, 135 (2013)
[19]	A.R. Antoniswamy, A.J. Carpenter, J.T. Carter, L.G. J. Mater. Eng. Perform. 22, 3389(2013)
[20]	F.K. Chen, T.B. Huang, C.K. Chang, Inter. J. Mach. Tools Manuf. 43, 1553(2003)
[21]	F. Kabirian, A.S. Khan, T. Gna¨upel-Herlod, Int. J. Plast. 68, 1(2015)
[22]	A. Chapuis, J.H. Driver, Acta Mater. 59, 1986 (2011)
[23]	H.L. Kim, W.K. Bang, Y.W. Chang, Mater. Sci. Eng. A 528,5356 (2011)
[24]	H. Li, Q.Q. Duan, X.W. Li, Z.F. Zhang, Mater. Sci. Eng. A 466,38 (2007)
[25]	L.L. Li, P. Zhang, Z.J. Zhang, H.F. Zhou, S.X. Qu, J.B. Yang,Z.F. Zhang, Acta Mater. 73, 167(2014)
[26]	A. Jain, S.R. Agnew, Mater. Sci. Eng. A 462, 29 (2007)
[27]	J.G. Yun, Y. Yan, F.W. Long, X.W. Li, Mater. Trans. 54, 1709(2013)
[28]	M.T. Tucker, M.F. Horstemeyer, P.M. Gullett, H. EI Kadiri,W.R. Whittington, Scr. Mater. 60, 182(2009)
[29]	Q. Liu, Acta Metall. Sin. 46, 1458(2010). (in Chinese)
[30]	R.O. Kaibyshev, B.K. Sokolov, A.M. Galiyev, Texture Microstruct.32, 47(1999)
[31]	J.A. Mater. Sci. Eng.A 355, 68 (2003)
[32]	L. Wen, P. Chen, Z.F. Tong, B.Y. Tang, L.M. Peng, W.J. Ding,Eur. Phys. J. B 72, 397 (2009)
[33]	A.E. Smith, Sur. Sci. 601, 5762(2007)
[34]	S.E. Ion, F.J. Humphreys, S.H. White, Acta Metall. 30, 1909 (1982)
[35]	Z.Q. Cui, Metallurgy and Heat Treatment (Mechanical Industry Press, Beijing, 2002), p. 206. (in Chinese)
[36]	F.W. Long, Q.W. Jiang, L. Xiao, X.W. Li, Mater. Trans. 52,1617(2011)