Selection of Twin Variants in Dynamic Plastic Deformation of Pure Ti at Liquid Nitrogen Temperature
GAO Dong1, ZHOU Yu2(), YU Ze3, SANG Baoguang1()
1.School of Mechanical Engineering and Automation, Dalian Polytecnic University, Dalian 116034, China 2.Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China 3.AVIC Shenyang Aircraft Company Limited, Shenyang 110850, China
Cite this article:
GAO Dong, ZHOU Yu, YU Ze, SANG Baoguang. Selection of Twin Variants in Dynamic Plastic Deformation of Pure Ti at Liquid Nitrogen Temperature. Acta Metall Sin, 2022, 58(9): 1141-1149.
Pure Ti can form twins during deformation due to the hcp crystal structure, and some kinds of twins can easily form under certain conditions, thus affecting the properties of materials. It has considerable influence on the properties of materials through the regulation of twin types and variants. This work investigates the effect of the dislocation slip of adjacent grains on the selection of twin variants during the deformation of pure Ti. The dynamic plastic deformation (DPD) of commercially pure Ti (99.9%) was performed at liquid nitrogen temperature (-196oC). The microstructure before and after the deformation was observed using EBSD. The influence of twinning on Schmid factor (m) before and after deformation was investigated, and a mechanism for selecting twin variants of polycrystalline pure Ti was proposed. The results show that after DPD at liquid nitrogen temperature, high-density primary twins appeared in pure Ti, followed by secondary and double twins. After twinning, the Schmid factor of basal slip changed noticeably, and the m of a large number of grains was close to 0.5. Based on the geometric compatibility factor (m') of the original slip and twin matching relationship and the Schmid factor of an adjacent grain (m1), a new orientation compatibility factor ω (ω = m1·m') was established, and the selection of twin variants in the plastic deformation of polycrystalline pure titanium was quantitatively analyzed. It was discovered that the ω determines the selection of twin variants in pure Ti, and the pyramidal slip <a> of the adjacent grain plays a significant role in promoting the initiation of twin variants.
Fund: Joint Research and Development Fund of Liaoning Province and Shenyang National Laboratory for Materials Science(2019JH3/30100030);Young Talents Project of Shenyang National Laboratory for Materials Science, and Natural Science Foundation Project of Liaoning Provincial Department of Education(J2020050)
About author: SANG Baoguang, associate professor, Tel: (0411)86324505, E-mail: sangbg@dlpu.edu.cn;ZHOU Yu, associate professor, Tel: (024)83970971, E-mail: yzhou@imr.ac.cn
Fig.1 Schematic of the seleced position of pure Ti sample (ND—normal direction, TD—transverse direction, RD—rolling direction)
Fig.2 EBSD images (a, b), (0001) pole figures (c, d), and image quality maps (e, f) of pure Ti before (a, c, e) and after (b, d, f) dynamic plastic deformation (DPD)
Type of twin
Misorientation angle
and axis
Frequency of twin
%
{ }
85° < >
7.87
{ }
57.2° < >
0.02
{ }
35° < >
0.15
{ }
64.4° < >
11.50
{ }
86.8° < >
0.50
{ }
77° < >
1.20
Total
-
21.24
Table 1 Frequencies of twinning boundaries in pure Ti after DPD
Fig.3 Microstructures of typical areas in pure Ti after DPD at liquid nitrogen temperature (a) secondary twin (b, d) double twin (c) tertiary twin
Fig.4 TEM images of rich twins (a) and twins nucleate at grain boundaries (b) in pure Ti after DPD at liquid nitrogen temperature (GB—grain boundary)
Type of Burgers vector
Slip direction
Slip plane
Total number of slip system
Independent number of slip system
Basal <a>
< >
{0002}
3
2
Prismatic <a>
< >
{ }
3
2
Pyramidal <a>
< >
{ }
6
4
Pyramidal <c + a>
< >
{ }
6
5
Table 2 Slip systems of Ti[25]
Fig.5 Schmid factors (m) in basal slip (a, e), prismatic slip (b, f), pyramidal <a> slip (c, g), and pyramidal <c + a> slip (d, h) before (a-d) and after (e-h) DPD (σ—compression direction)
Fig.6 m in basal slip (a), prismatic slip (b), pyramidal <a> slip (c), and pyramidal <c + a> slip (d) before and after DPD
Fig.7 Schematics of orientation compatibility factor (ω) (bd—slip direction of the dislocation, bt —twin direction, nd—normal direction of the slip plane of the dislocation, nt—normal direction of the twin plane, ϕ—included angle between the normal direction of the twin plane and the normal direction of the slip plane, κ—included angle between the twin direction and the slip direction) (a) stereogram (b) planar graph
Fig.8 EBSD maps of twins and the choose of twin variants (The dots represent the six possible twin variants (V), and the rectangles represent the actual twin variants initiated (M)) (a) twin A (b) twin B (c) twin C (d) twin D
Twin
Twin
m
m'
ω
variant
Basal
Prismatic
Pyramidal
Pyramidal
Basal
Prismatic
Pyramidal
Pyramidal
<a>
<a>
<a>
<a + c>
<a>
<a>
<a>
<c + a>
A
V1
0.431
0.582
0.497
0.716
0.624
0.148
0.205
0.285*
0.170
V2
0.013
0.121
0.453
0.456
0.833
0.031
0.051
0.075
0.101
V3
0.282
0.039
0.201
0.195
0.825
0.010
0.029
0.035
0.253
V4
0.446
0.355
0.651
0.741
0.789
0.067
0.218
0.182
0.387
V5
0.016
0.811
0.339
0.674
0.470
0.104
0.151
0.198
0.099
V6
0.270
0.975
0.190
0.633
0.340
0.150
0.085
0.295
0.068
B
V1
0.214
0.561
0.675
0.861
0.314
0.132
0.149
0.092
0.120
V2
0.013
0.921
0.145
0.473
0.546
0.126
0.065
0.195
0.094
V3
0.120
0.231
0.720
0.742
0.611
0.053
0.319
0.260
0.163
V4
0.483
0.157
0.668
0.659
0.470
0.042
0.197
0.258
0.085
V5
0.063
0.430
0.224
0.296
0.969
0.058
0.089
0.116
0.203
V6
0.338
0.454
0.678
0.813
0.300
0.103
0.301
0.405*
0.030
C
V1
0.215
0.406
0.644
0.760
0.626
0.082
0.158
0.116
0.208
V2
0.006
0.824
0.285
0.645
0.501
0.227
0.086
0.099
0.076
V3
0.093
0.179
0.588
0.600
0.651
0.085
0.178
0.238
0.106
V4
0.486
0.033
0.448
0.409
0.721
0.009
0.110
0.128
0.177
V5
0.060
0.048
0.234
0.225
0.770
0.020
0.041
0.063
0.142
V6
0.299
0.783
0.478
0.795
0.523
0.228
0.145
0.316*
0.089
D
V1
0.216
0.741
0.567
0.852
0.505
0.336
0.119
0.142
0.104
V2
0.354
0.079
0.154
0.169
0.814
0.036
0.031
0.068
0.137
V3
0.018
0.108
0.631
0.606
0.604
0.049
0.132
0.202
0.124
V4
0.134
0.037
0.542
0.494
0.690
0.014
0.156
0.217
0.107
V5
0.479
0.855
0.194
0.580
0.420
0.388
0.041
0.233*
0.076
V6
0.061
0.490
0.679
0.831
0.571
0.191
0.196
0.179
0.090
Table 3 Selection parameters of twin variants of pure Ti
1
Fu J, Ding H, Huang Y, et al. Influence of phase volume fraction on the grain refining of a Ti-6Al-4V alloy by high-pressure torsion [J]. J. Mater. Res. Technol., 2015, 4: 2
doi: 10.1016/j.jmrt.2014.10.006
2
Li X M, Sun W L, Han Y, et al. Preparation of Ti(C x N1 - x ) thick films on titanium by plasma electrolytic carbonitriding [J]. Acta Metall. Sin., 2008, 44: 1105
Partridge P G. The crystallography and deformation modes of hexagonal close-packed metals [J]. Int. Mater. Rev., 1967, 12: 169
doi: 10.1179/imr.1967.12.1.169
4
Groves G W, Kelly A. Independent slip systems in crystals [J]. Philos. Mag., 1963, 8: 877
doi: 10.1080/14786436308213843
5
Mises R V. Mechanik der plastischen formänderung von kristallen [J]. Z. Angew. Math. Mech., 1928, 8: 161
doi: 10.1002/zamm.19280080302
6
Huang W, Wang Y, Li Z R, et al. Influences of temperature and strain rate on deformation twinning of polycrystalline titanium [J]. Chin. J. Nonferrous. Met., 2008, 18: 1440
Chichili D R, Ramesh K T, Hemker K J. The high-strain-rate response of alpha-titanium: Experiments, deformation mechanisms and modeling [J]. Acta Mater., 1998, 46: 1025
doi: 10.1016/S1359-6454(97)00287-5
8
Choi S W, Won J W, Lee S, et al. Deformation twinning activity and twin structure development of pure titanium at cryogenic temperature [J]. Mater. Sci. Eng., 2018, A738: 75
9
Xu F, Zhang X Y, Ni H T, et al. {11 2 ¯ 4} deformation twinning in pure Ti during dynamic plastic deformation [J]. Mater. Sci. Eng., 2012, A541: 190
10
Gurao N P, Kapoor R, Suwas S. Deformation behaviour of commercially pure titanium at extreme strain rates [J]. Acta Mater., 2011, 59: 3431
doi: 10.1016/j.actamat.2011.02.018
11
Zherebtsov S V, Dyakonov G S, Salem A A, et al. Formation of nanostructures in commercial-purity titanium via cryorolling [J]. Acta Mater., 2013, 61: 1167
doi: 10.1016/j.actamat.2012.10.026
12
Li Q, Xu Y B, Bassim M N. Dynamic mechanical behavior of pure titanium [J]. J. Mater. Process. Technol., 2004, 155-156: 1889
doi: 10.1016/j.jmatprotec.2004.04.327
13
Tao N R, LU K. Dynamic plastic deformation (DPD): A novel technique for synthesizing bulk nanostructured metals [J]. J. Mater. Sci. Technol., 2007, 23: 771
doi: 10.1179/174328407X185802
14
Li Y S, Zhang Y, Tao N R, et al. Effect of the Zener-Hollomon parameter on the microstructures and mechanical properties of Cu subjected to plastic deformation [J]. Acta Mater., 2009, 57: 761
doi: 10.1016/j.actamat.2008.10.021
15
Guan D K, Wynne B, Gao J H, et al. Basal slip mediated tension twin variant selection in magnesium WE43 alloy [J]. Acta Mater., 2019, 170: 1
doi: 10.1016/j.actamat.2019.03.018
16
Christian J W. Deformation twinning [A]. The Theory of Transformations in Metals and Alloys [M]. Oxford: Elsevier Ltd., 2002: 859
17
Lebensohn R A, Tomé C N. A self-consistent anisotropic approach for the simulation of plastic deformation and texture development of polycrystals: Application to zirconium alloys [J]. Acta Metall. Mater., 1993, 41: 2611
doi: 10.1016/0956-7151(93)90130-K
18
Reid C N, Gilbert A, Hahn G T. Twinning, slip and catastrophic flow in niobium [J]. Acta Metall., 1966, 14: 975
doi: 10.1016/0001-6160(66)90218-5
19
Wang L, Yang Y, Eisenlohr P, et al. Twin nucleation by slip transfer across grain boundaries in commercial purity titanium [J]. Metall. Mater. Trans., 2009, 41A: 421
20
Chun Y B, Yu S H, Semiatin S L, et al. Effect of deformation twinning on microstructure and texture evolution during cold rolling of CP-titanium [J]. Mater. Sci. Eng., 2005, A398: 209
21
Lee M S, Jo A R, Hwang S K, et al. The role of strain rate and texture in the deformation of commercially pure titanium at cryogenic temperature [J]. Mater. Sci. Eng., 2021, A827: 142042
22
Won J W, Lee J H, Jeong J S, et al. High strength and ductility of pure titanium via twin-structure control using cryogenic deformation [J]. Scr. Mater., 2020, 178: 94
doi: 10.1016/j.scriptamat.2019.11.009
23
Zeng Z P, Zhang Y S, Jonsson S. Deformation behaviour of commercially pure titanium during simple hot compression [J]. Mater. Des., 2009, 30: 3105
doi: 10.1016/j.matdes.2008.12.002
24
Dahlgren S D, Nicholson W L, Merz M D, et al. Microstructural analysis and tensile properties of thick copper and nickel sputter deposits [J]. Thin Solid Films, 1977, 40: 345
doi: 10.1016/0040-6090(77)90136-5
25
Yoo M H. Slip, twinning, and fracture in hexagonal close-packed metals [J]. Metall. Trans., 1981, 12A: 409
26
Qin H, Jonas J J, Yu H B, et al. Initiation and accommodation of primary twins in high-purity titanium [J]. Acta Mater., 2014, 71: 293
doi: 10.1016/j.actamat.2014.03.025
27
Zhang Z F, Shao C W, Wang B, et al. Tensile and fatigue properties and deformation mechanisms of twinning-induced plasticity steels [J]. Acta Metall. Sin., 2020, 56: 476
Yoo M H, Morris J R, Ho K M, et al. Nonbasal deformation modes of HCP metals and alloys: Role of dislocation source and mobility [J]. Metall. Mater. Trans., 2002, 33A: 813
29
Luster J, Morris M A. Compatibility of deformation in two-phase Ti Al alloys: Dependence on microstructure and orientation relationships [J]. Metall. Mater. Trans., 1995, 26A: 1745
