Detwinning Behaviors and Dynamic Mechanical Properties of Precompressed AZ31 Magnesium Alloy Subjected to High Strain Rates Impact
CHEN Yang, MAO Pingli(), LIU Zheng, WANG Zhi, CAO Gengsheng
Key Laboratory of Magnesium Alloys and the Processing Technology of Liaoning Province, School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870, China
Cite this article:
CHEN Yang, MAO Pingli, LIU Zheng, WANG Zhi, CAO Gengsheng. Detwinning Behaviors and Dynamic Mechanical Properties of Precompressed AZ31 Magnesium Alloy Subjected to High Strain Rates Impact. Acta Metall Sin, 2022, 58(5): 660-672.
To investigate the detwinning behaviors and dynamic mechanical properties of a precompressed rolled AZ31 magnesium alloy sheet impacted under high strain rates, the as-received sheet was precompressed along the rolling direction (RD) to the true strain of 4% for inducing { } tensile twins. The as-received and precompressed rolled AZ31 magnesium alloy sheets were impacted along the normal direction (ND) using a split Hopkinson pressure bar experiment apparatus at strain rates of 700, 1000, 1300, and 1600 s-1. Microstructural characteristics of the as-received, precompressed, and impacted specimens were analyzed and compared by an electron backscatter diffraction technology. The results show that in the precompressed specimen, the density of the basal texture was weakened and a new twin texture with the c-axis paralled to RD was formed. The average grain size of the precompressed specimen decreased visibly as a result of the parent grains being subdivided by tensile twin boundaries. The dominant deformation mechanism of the precompressed rolled AZ31 magnesium alloy impacted along ND is detwinning. With increasing the strain rate, the initial basal texture recovered, the average grain size increased, and the average twin thickness decreased. Compared with the precompressed specimen, the as-received specimen impacted along ND exhibited higher strength and lower formability. The precompressed specimen demonstrated greater strain rate sensitivity during plastic deformation.
Fig.1 EBSD analysis results of the rolled AZ31 magnesium alloy sheet after homogenization (TD and RD represent transverse direction and rolling direction of the sheet, respectively) (a) inverse pole figure (b) grain boundary figure (c) grain size distribution (d) {0001} pole figure (e) misorientation angle distribution
Fig.2 EBSD analysis results of the rolled AZ31 magnesium alloy sheet precompressed along RD with a true strain of 4% (a) inverse pole figure (b) grain boundary figure (c) grain size distribution (d) {0001} pole figure (e) misorientation angle distribution
Fig.3 Local enlarged figure of the rectangular region in Fig.2a (a) and misorientation angle distribution along the direction indicated by the arrow in Fig.3a (b)
Fig.4 EBSD analysis results of the precompressed rolled AZ31 magnesium alloy impacted along normal direction (ND) under the strain rate of 700 s-1 (a) inverse pole figure (b) grain boundary figure (c) grain size distribution (d) {0001} pole figure (e) misorientation angle distribution
Fig.5 EBSD analysis results of the precompressed rolled AZ31 magnesium alloy impacted along ND under the strain rate of 1000 s-1 (a) inverse pole figure (b) grain boundary figure (c) grain size distribution (d) {0001} pole figure (e) misorientation angle distribution
Fig.6 EBSD analysis results of the precompressed rolled AZ31 magnesium alloy specimen impacted along ND under the strain rate of 1300 s-1 (a) inverse pole figure (b) grain boundary figure (c) grain size distribution (d) {0001}pole figure (e) misorientation angle distribution
Fig.7 EBSD analysis results of the precompressed rolled AZ31 magnesium alloy specimen impacted along ND under the strain rate of 1600 s-1 (a) inverse pole figure (b) grain boundary figure (c) grain size distribution (d) {0001}pole figure (e) misorientation angle distribution
Fig.8 Number of tensile twins in precompressed rolled AZ31 magnesium alloy specimen (a) and impacted along ND under 700 s-1 (b), 1000 s-1 (c), 1300 s-1 (d), and 1600 s-1 (e)
Fig.9 Remaining tensile twin area fractions and twin thicknesses of the precompressed AZ31 magnesium alloy specimen impacted along ND under different strain rates
Fig.10 True stress-strain curves of the as-received (a) and precompressed (b) AZ31 magnesium alloy impacted along ND under different strain rates
Specimen
= 700 s-1
= 1000 s-1
= 1300 s-1
= 1600 s-1
σs
σp
σs
σp
σs
σp
σs
σp
As-received
113.2
345.6
128.9
419.7
135.4
458.6
144.5
498.1
Precompressed
98.7
228.1
102.5
348.8
107.3
415.2
112.2
488.8
Table 1 Yield stress and peak stress of the as-received and precompressed AZ31 magnesium alloy specimen impacted along ND under different strain rates
Specimen
= 0.005
= 0.01
= 0.025
= 0.05
As-received
0.227
0.269
0.232
0.166
0.224
Precompressed
0.301
0.179
0.295
0.438
0.303
Table 2 Strain rate sensitivity indexs of the as-received and precompressed AZ31 magnesium alloy specimen impacted along ND under different true strains (ε) at = 700 s-1, = 1600 s-1
Fig.11 Schematics showing the change of orientation during detwinning (a) initial orientation (b) after precompression along RD (c) after impaction along ND
1
Watanabe H, Ishikawa K. Effect of texture on high temperature deformation behavior at high strain rates in a Mg-3Al-1Zn alloy [J]. Mater. Sci. Eng., 2009, A523: 304
2
Khosravani A, Fullwood D T, Adams B L, et al. Nucleation and propagation of { 10 1 ¯ 2 } twins in AZ31 magnesium alloy [J]. Acta Mater., 2015, 100: 202
doi: 10.1016/j.actamat.2015.08.024
3
Shan Z W, Liu B Y. The mechanism of { 10 1 ¯ 2 } deformation twinning in magnesium [J]. Acta Metall. Sin., 2016, 52: 1267
Li X D, Mao P L, Liu Y Y, et al. Anisotropy and deformation mechanisms of as-extruded Mg-3Zn-1Y magnesium alloy under high strain rates [J]. Acta Metall. Sin., 2018, 54: 557
Luque A, Ghazisaeidi M, Curtin W A. A new mechanism for twin growth in Mg alloys [J]. Acta Mater., 2014, 81: 442
doi: 10.1016/j.actamat.2014.08.052
6
Lou C, Zhang X Y, Ren Y. Twinning characteristic of AZ31 magnesium alloy during dynamic plastic deformation [J]. Chin. J. Nonferrous Met., 2015, 25: 2642
Wu W, Gao Y F, Li N, et al. Intragranular twinning, detwinning, and twinning-like lattice reorientation in magnesium alloys [J]. Acta Mater., 2016, 121: 15
doi: 10.1016/j.actamat.2016.08.058
8
Huang H T, Godfrey A, Zheng J P, et al. Influence of local strain on twinning behavior during compression of AZ31 magnesium alloy [J]. Mater. Sci. Eng., 2015, A640: 330
9
Wang B S, Deng L P, Chapuis A, et al. Study of twinning behavior of AZ31 Mg alloy during plane strain compression [J]. Acta Metall. Sin., 2015, 51: 1441
Yan Y Q, Luo J R, Zhang J S, et al. Study on the microstructural evolution and mechanical properties control of a strong textured AZ31 magnesium alloy sheet during cryorolling [J]. Acta Metall. Sin., 2017, 53: 107
Hong S G, Park S H, Lee C S. Role of { 10 1 ¯ 2 } twinning characteristics in the deformation behavior of a polycrystalline magnesium alloy [J]. Acta Mater., 2010, 58: 5873
doi: 10.1016/j.actamat.2010.07.002
12
Hou D W, Li Q Z, Wen H M. Study of reversible motion of { 10 1 ¯ 2 } tensile twin boundaries in a magnesium alloy during strain path changes [J]. Mater. Lett., 2018, 231: 84
doi: 10.1016/j.matlet.2018.08.019
13
Lee J U, Song S W, Kim Y, et al. Effects of { 10 1 ¯ 2 } twins on dynamic torsional properties of extruded AZ31 magnesium alloy [J]. Met. Mater. Int., 2018, 24: 283
doi: 10.1007/s12540-018-0030-x
14
Mokdad F, Chen D L, Li D Y. Twin-twin interactions and contraction twin formation in an extruded magnesium alloy subjected to an alteration of compressive direction [J]. J. Alloys Compd., 2018, 737: 549
doi: 10.1016/j.jallcom.2017.12.043
15
Chen H C, Liu T M, Hou D W, et al. Improving the mechanical properties of a hot-extruded AZ31 alloy by { 10 1 ¯ 2 } twinning lamella [J]. J. Alloys Compd., 2016, 680: 191
doi: 10.1016/j.jallcom.2016.04.106
16
Park S H, Hong S G, Lee J H, et al. Texture evolution of rolled Mg-3Al-1Zn alloy undergoing a { 10 1 ¯ 2 } twinning dominant strain path change [J]. J. Alloys Compd., 2015, 646: 573
doi: 10.1016/j.jallcom.2015.05.194
17
Long Z X, Liu T M, He J J, et al. The effects of pre-strain and subsequent annealing on the yielding behavior in a rolled magnesium alloy AZ31 [J]. J. Mater. Eng. Perform., 2015, 24: 16
doi: 10.1007/s11665-014-1284-1
18
Song B, Xin R L, Sun L Y, et al. Enhancing the strength of rolled ZK60 alloys via the combined use of twinning deformation and aging treatment [J]. Mater. Sci. Eng., 2013, A582: 68
19
Sun Q, Xia T, Tan L, et al. Influence of { 10 1 ¯ 2 } twin characteristics on detwinning in Mg-3Al-1Zn alloy [J]. Mater. Sci. Eng., 2018, A735: 243
20
Sarker D, Friedman J, Chen D L. De-twinning and texture change in an extruded AM30 magnesium alloy during compression along normal direction [J]. J. Mater. Sci. Technol., 2015, 31: 264
doi: 10.1016/j.jmst.2014.11.018
21
Huang H T, Godfrey A, Liu W, et al. Study on twinning behaviors during multi-directional compression for AZ31 magnesium alloy by EBSD [J]. J. Chin. Electron Microsc. Soc., 2011, 30: 294
Lou C, Zhang X Y, Wang R H, et al. Effects of untwinning and { 10 1 ¯ 2 } twin lamellar structure on the mechanical properties of Mg alloy [J]. Acta Metall. Sin., 2013, 49: 291
doi: 10.3724/SP.J.1037.2012.00582
Proust G, Tomé C N, Jain A, et al. Modeling the effect of twinning and detwinning during strain-path changes of magnesium alloy AZ31 [J]. Int. J. Plast., 2009, 25: 861
doi: 10.1016/j.ijplas.2008.05.005
24
Wang R F, Mao P L, Liu Y Y, et al. Influence of pre-twinning on high strain rate compressive behavior of AZ31 Mg-alloys [J]. Mater. Sci. Eng., 2018, A742: 309
25
Yu Q, Wang J, Jiang Y Y, et al. Twin-twin interactions in magnesium [J]. Acta Mater., 2014, 77: 28
doi: 10.1016/j.actamat.2014.05.030
26
Guan D K, Rainforth W M, Gao J H, et al. Individual effect of recrystallisation nucleation sites on texture weakening in a magnesium alloy: Part 1—double twins [J]. Acta Mater., 2017, 135: 14
doi: 10.1016/j.actamat.2017.06.015
27
Wang X X, Mao P L, Wang R F, et al. Role of { 10 1 ¯ 2 } twinning in the anisotropy and asymmetry of AZ31 magnesium alloy under high strain rate deformation [J]. Mater. Sci. Eng., 2020, A772: 138814
28
Xiao J, Shu D W. Compressive behavior and constitutive analysis of AZ31B magnesium alloy over wide range of strain rates and temperatures [J]. Met. Mater. Int., 2015, 21: 823
doi: 10.1007/s12540-015-5120-4
29
Zhang Y, Liu T M, Xu S, et al. Detwinning behavior of an extruded AZ31 magnesium alloy during uniaxial compression [J]. Trans. Mater. Heat Treat., 2013, 34(8): 26
Guo L L, Chen Z C, Gao L. Effects of grain size, texture and twinning on mechanical properties and work-hardening behavior of AZ31 magnesium alloys [J]. Mater. Sci. Eng., 2011, A528: 8537
31
Xi G Q, Chen Y, Chen S, et al. Study on twinning-detwinning behavior of magnesium alloy by Situ EBSD [J]. J. Chongqing Univ. Technol. (Nat. Sci.), 2020, 34(9): 147
Chen Y, Mao P L, Wang Z, et al. High strain rate deformation behaviors experimental study and numerical simulation of rolled AZ31 magnesium alloy loaded along different directions [J]. Chin. J. Nonferrous Met., 2020, 30: 997
