A superior strength-ductility synergy of Al0.1CrFeCoNi high-entropy alloy with fully recrystallized ultrafine grains and annealing twins

doi:10.1016/j.jmst.2022.06.003

Abstract

Abstract:

Grain refinement usually makes the materials stronger, while ductility has a dramatic loss. Here, a superior tensile strength-ductility synergy in a fully recrystallized ultrafine-grained (UFG) Al_0.1CrFeCoNi with abundant annealing twins was achieved by cold rolling at room temperature and short-time annealing. The microstructure characterization using electron backscattered scattering diffraction demonstrates that abundant geometrically necessary dislocations (GNDs) gather around the grain boundaries and twin boundaries after tensile deformation. Although coarse-grained (CG) samples undergo a larger plastic deformation than UFG samples, the GND density decreases with grain size ranging from UFG to CG. Transmission electron microscopy results reveal that the annealing twin boundary, which effectively hinders the dislocation slip and stores dislocation in grain interior, and the activation of multiple deformation twins are responsible for the superior strength-ductility synergy and work hardening ability. In addition, the yield strength of fully recrystallized Al_0.1CrFeCoNi follows a Hall-Petch relationship (σ_y = 24 + 676 d^-1/2), where d takes into account both grain boundaries and annealing twin boundaries. The strengthening effects of grain boundaries and annealing twin boundaries were also evaluated separately.

Key words: High-entropy alloy, Ultrafine grains, Annealing twins, Strength, Ductility

Jiahao Li, Kejie Lu, Xiaojun Zhao, Xinkai Ma, Fuguo Li, Hongbo Pan, Jieming Chen. A superior strength-ductility synergy of Al_0.1CrFeCoNi high-entropy alloy with fully recrystallized ultrafine grains and annealing twins[J]. J. Mater. Sci. Technol., 2022, 131: 185-194.

Figures/Tables 13

Fig. 1. Microstructural characterization of Al0.1CoCrFeNi annealed at 900 °C for 2 h. (a) IPF map. (b) EDS maps, confirming the chemical homogeneity in the CG sample. (c) Misorientation distribution. (d) Grain size distribution. The fraction of twin boundaries (TBs) is 45.8% and the average grain size is 17.5 μm. (e) TEM image, showing the dislocation-free microstructure and the annealing twins.

Fig. 2. XRD pattern of the cold-rolled and annealed Al0.1CoCrFeNi samples before tensile deformation.

Fig. 3. Microstructural evolution with increasing annealing time for (a) CR900-1.5, (b) CR900-2.5, (c) CR900-5, and (d) CR900-30. For GB maps, the blue line means the low-angle grain boundary, the black line means the high-angle grain boundary, and the red line means the ATs (Σ3, 60° <111>).

Fig. 4. Mechanical response of the annealed Al0.1CoCrFeNi. (a) Engineering stress-strain curves. (b) Corresponding work hardening rate as a function of true strain. (c) Yield strength σy vs uniform elongation δu for FCC HEAs with a single phase. Our data are marked as the red stars, while all the literature data are collected from Refs. [28], [29], [30], [31], [32], [33]. (d) Product of ultimate tensile strength σb and δu as a function of σy normalized by Young's modulus (220 GPa) for Al0.1CoCrFeNi, other FCC HEAs, and the selected metals [14].

Table 1. Mechanical properties (yield strength σy, ultimate tensile strength σb, uniform elongation δu, and the product of σb and δu) of Al0.1CoCrFeNi.

Samples	d (µm)	d₀ (µm)	σ_y (MPa)	σ_b (MPa)	δ_u (%)	σ_b·δ_u (GPa%)
CR	-	-	990 ± 10	1511 ± 16	5.3 ± 2	7.93
CR900-1.5	0.58	1.2	885 ± 15	998 ± 11	23.4 ± 4	23.4
CR900-2.5	1.4	2.9	656 ± 9	907 ± 10	38.7 ± 2	35.1
CR900-5	2.5	4.4	453 ± 11	805 ± 9	48.1 ± 1	38.7
CR900-30	4.2	13.3	328 ± 7	726 ± 13	53.5 ± 2	38.8
CG	17.5	47.6	180 ± 13	539 ± 17	52.9 ± 3	28.5

Fig. 5. Inverse pole figure (IPF) maps, grain boundary (GB) maps, and the corresponding grain size statistics of the annealed Al0.1CoCrFeNi after tension failure: (a) CR900-1.5, (b) CR900-2.5, (c) CR900-5, (d) CR900-30, (e) CG.

Fig. 6. Microstructure evolution before and after tensile deformation (a) LAGBs and (b) ATs.

Fig. 7. Geometrically necessary dislocation (GND) density maps and the corresponding distributions in the annealed Al0.1CoCrFeNi after tension failure: (a) and (f) CR900-1.5, (b) and (g) CR900-2.5, (c) and (h) CR900-5, (d) and (i) CR900-30, (e) and (j) CG.

Fig. 8. {111} pole figures of the annealed Al0.1CoCrFeNi before and after tension failure, showing the evolution of the 〈111〉 texture: (a) and (f) CR900-1.5, (b) and (g) CR900-2.5, (c) and (h) CR900-5, (d) and (i) CR900-30, (e) and (j) CG.

Fig. 9. Fractography of the annealed Al0.1CoCrFeNi after tensile deformation: (a) CR, (b) CR900-1.5, (c) CR900-2.5, (d) CR900-5, (e) CR900-30, (f) CG.

Fig. 10. TEM characterizations of deformed substructures for CR900-1.5 at different tensile strains. (a) ε = 0, showing the fully recrystallized UFGs and ATs. (b) ε = 3%, showing the dislocations pile-up at GBs and ATs. (c) and (d) ε = 10%, showing the deformation-induced NTs. (e) SAED pattern of (d) along zone axis [011]. (f) ε = 20%, showing the hindering effect of TBs and GBs on dislocation slip.

Fig. 11. TEM characterizations of deformed substructures for CR900-5 at different tensile strains. (a) ε = 0%, showing the ATs. (b) ε = 3%, showing the deformation-induced twins. (c) Corresponding high-resolution TEM (HRTEM) of (b). (d) ε = 10%, showing the deformation-induced secondary deformation twins. (e) SAED pattern of (d). (f) ε = 20%, showing the dislocation tangles around GBs and ATs.

Fig. 12. Yield strength vs inverse square root of grain size d (including the annealing twin boundaries), showing the contributions from different strengthening mechanisms in the annealed Al0.1CoCrFeNi.

References 54

[1]	J. Su, D. Raabe, Z.M. Li, Acta Mater. 163 (2019) 40-54. DOI URL
[2]	Y. Zhang, T.T. Zuo, Z. Tang, M.C. Gao, K.A. Dahmen, P.K. Liaw, Z.P. Lu, Prog. Mater. Sci. 61 (2014) 1-93. DOI URL
[3]	D.B. Miracle, O.N. Senkov, Acta Mater. 122 (2017) 448-511. DOI URL
[4]	J. Li, H.T. Chen, Q.H. Fang, C. Jiang, Y. Liu, P.K. Liaw, Int. J. Plast. 133 (2020) 102819.
[5]	Q.H. Fang, Y. Chen, J. Li, C. Jiang, B. Liu, Y. Liu, P.K. Liaw, Int. J. Plast. 114 (2019) 161-173. DOI URL
[6]	X.B. Feng, J.Y. Zhang, Y.Q. Wang, Z.Q. Hou, K. Wu, G. Liu, J. Sun, Int. J. Plast. 95 (2017) 264-277. DOI URL
[7]	M. Komarasamy, N. Kumar, Z. Tang, R. Mishra, P. Liaw, Mater. Res. Lett. 3 (2015) 30-34. DOI URL
[8]	B. Schuh, F. Mendez-Martin, B. Völker, E.P. George, H. Clemens, R. Pippan, A. Hohenwarter, Acta Mater. 96 (2015) 258-268. DOI URL
[9]	J. Yang, J.W. Qiao, S.G. Ma, G.Y. Wu, D. Zhao, Z.H. Wang, J. Alloy. Compd. 795 (2019) 269-274. DOI
[10]	Z. Wu, H. Bei, G.M. Pharr, E.P. George, Acta Mater. 81 (2014) 428-441. DOI URL
[11]	B. Gludovatz, A. Hohenwarter, D. Catoor, E.H. Chang, E.P. George, R.O. Ritchie, Science 345 (2014) 1153-1158. DOI PMID
[12]	S.W. Wu, G. Wang, Q. Wang, Y.D. Jia, J. Yi, Q.J. Zhai, J.B. Liu, B.A. Sun, H.J. Chu, J. Shen, P.K. Liaw, C.T. Liu, T.Y. Zhang, Acta Mater. 165 (2019) 444-458. DOI
[13]	Y. Jo, S. Jung, W. Choi, S.S. Sohn, H. Kim, B. Lee, N.J. Kim, S. Lee, Nat. Commun. 8 (2017) 15719. DOI PMID
[14]	Q.S. Pan, L.X. Zhang, R. Feng, Q.H. Lu, K. An, A.C. Chuang, J.D. Poplawsky, P.K. Liaw, L. Lu, Science 374 (2021) 984-989. DOI URL
[15]	A. Zaddach, C. Niu, C. Koch, D. Irving, JOM 65 (2013) 1780-1789. DOI URL
[16]	N.B. Zhang, J. Xu, Z.D. Feng, Y.F. Sun, J.Y. Huang, X.J. Zhao, X.H. Yao, S. Chen, L. Lu, S.N. Luo, J. Mater. Sci. Technol. 128 (2022) 1-9. DOI
[17]	S.J. Sun, Y.Z. Tian, H.R. Lin, H.J. Yang, X.G. Dong, Y.H. Wang, Z.F. Zhang, Mater. Sci. Eng. A 712 (2018) 603-607. DOI URL
[18]	S.W. Wu, G. Wang, J. Yi, Y.D. Jia, I. Hussain, Q.J. Zhai, P.K. Liaw, Mater. Res. Lett. 5 (2017) 276-283. DOI URL
[19]	H. Jeong, W. Kim, J. Mater. Sci. Technol. 111 (2022) 152-166. DOI
[20]	R.E. Kubilay, W. Curtin, Acta Mater. 216 (2021) 117119.
[21]	J. Gordon, R. Lim, M. Wilkin, D. Pagan, R. Lebensohn, A. Rollett, Acta Mater. 215 (2021) 117120.
[22]	Z. Chen, H.B. Xie, H.L. Yan, X.Y. Pang, Y.H. Wang, G.L. Wu, L.J. Zhang, H. Tang, B. Gao, B. Yang, Y.Z. Tian, H.Y. Gou, G.W. Qin, J. Mater. Sci. Technol. 126 (2022) 228-236. DOI URL
[23]	Y.Z. Tian, Y. Bai, L.J. Zhao, S. Gao, H.K. Yang, A. Shibata, Z.F. Zhang, N. Tsuji, Mater. Charact. 126 (2017) 74-80. DOI URL
[24]	S.J. Sun, Y.Z. Tian, H.R. Lin, X.G. Dong, Y.H. Wang, Z.J. Zhang, Z.F. Zhang, Mater. Des. 133 (2017) 122-127. DOI URL
[25]	P.J. Shi, W.L. Ren, T.X. Zheng, Z.M. Ren, X.L. Hou, J.C. Peng, P.F. Hu, Y.F. Gao, Y.B. Zhong, P.K. Liaw, Nat. Commun. 10 (2019) 489. DOI URL
[26]	Q.F. Wu, Z.J. Wang, F. He, Z.S. Yang, J.J. Li, J.C. Wang, J. Mater. Sci. Technol. 128 (2022) 71-81. DOI URL
[27]	W. Zhang, Z.C. Ma, C.F. Li, C.W. Guo, D.N. Liu, H.W. Zhao, L.Q. Ren, J. Mater. Sci. Technol. 114 (2022) 102-110. DOI
[28]	S.W. Wu, L. Xu, X.D. Ma, Y.F. Jia, Y.K. Mu, Y.D. Jia, G. Wang, C.T. Liu, Mater. Sci. Eng. A 805 (2021) 140523.
[29]	S.J. Sun, Y.Z. Tian, X.H. An, H.R. Lin, J.W. Wang, Z.F. Zhang, Mater. Today Nano 4 (2018) 46-53.
[30]	S.G. Ma, Y.J. Li, S. Li, B. Xu, T.W. Zhang, Z.M. Jiao, D. Zhao, Z.H. Wang, Mater. Sci. Eng. A 829 (2022) 142165.
[31]	B.B. He, B.M. Huang, S.H. He, Y. Qi, H.W. Yen, M.X. Huang, Mater. Sci. Eng. A 724 (2018) 11-16. DOI URL
[32]	N. Kumar, M. Komarasamy, P. Nelaturu, Z. Tang, P. Liaw, R. Mishra, JOM 67 (2015) 1007-1013. DOI URL
[33]	A. Zaddach, R. Scattergood, C. Koch, Mater. Sci. Eng. A 636 (2015) 373-378. DOI URL
[34]	D.D. Zhang, J.Y. Zhang, J. Kuang, G. Liu, J. Sun, Acta Mater. 220 (2021) 117288.
[35]	C. Slone, S. Chakraborty, J. Miao, E.P. George, M.J. Mills, S. Niezgoda, Acta Mater. 158 (2018) 38-52. DOI URL
[36]	X.L. Wu, M.X. Yang, F.P. Yuan, G.L. Wu, Y.J. Wei, X.X. Huang, Y.T. Zhu, Proc. Natl. Acad. Sci. 112 (2015) 14501-14505.
[37]	M. Schneider, E. George, T. Manescau, T. Záležák, J. Hunfeld, A. Dlouhý, G. Eggeler, G. Laplanche, Int. J. Plast. 124 (2020) 155-169. DOI URL
[38]	Z. Cheng, L.F. Bu, Y. Zhang, H.A. Wu, T. Zhu, H.J. Gao, L. Lu, Proc. Natl. Acad. Sci. 119 (2022) e2116808119.
[39]	H. Ran, R.R. Jin, Y.F. Wang, M.S. Wang, Q. He, F.J. Guo, Y. Wen, C.X. Huang, Mater. Sci. Eng. A 807 (2021) 140906.
[40]	G. Chen, J.W. Qiao, Z.M. Jiao, D. Zhao, T.W. Zhang, S.G. Ma, Z.H. Wang, Scr. Mater. 167 (2019) 95-100. DOI URL
[41]	X.L. Wu, Y.T. Zhu, MRS Bull. 46 (2021) 244-249.
[42]	J. Peng, L. Li, F. Li, B. Liu, S. Zherebtsov, Q.H. Fang, J. Li, N. Stepanov, Y. Liu, F. Liu, Int. J. Plast. 145 (2021) 103073.
[43]	X.X. Wu, D. Mayweg, D. Ponge, Z.M. Li, Mater. Scie. Eng. A 802 (2021) 140661.
[44]	X.Z. Gao, Y.P. Lu, J.Z. Liu, J. Wang, T.M. Wang, Y.H. Zhao, Materialia 8 (2019) 100485.
[45]	Z.M. Yang, D.S. Yan, W.J. Lu, Z.M. Li, Mater. Sci. Eng. A 801 (2021) 140441.
[46]	F. Otto, A. Dlouhý, C. Somsen, H. Bei, G. Eggeler, E.P. George, Acta Mater. 61 (2013) 5743-5755. DOI URL
[47]	K. Lu, Nat. Rev. Mater. 1 (2016) 1-13.
[48]	Z. Cheng, H.F. Zhou, Q.H. Lu, H.J. Gao, L. Lu, Science 362 (2018) eaau1925. DOI URL
[49]	W.H. Liu, Y. Wu, J.Y. He, T. Nieh, Z.P. Lu, Scr. Mater. 68 (2013) 526-529. DOI URL
[50]	S. Yoshida, T. Bhattacharjee, Y. Bai, N. Tsuji, Scr. Mater. 134 (2017) 33-36. DOI URL
[51]	X.D. Xu, P. Liu, A. Hirata, S.X. Song, T. Nieh, M.W. Chen, Materialia 4 (2018) 395-405. DOI URL
[52]	X.M. Wang, Y.T. Ding, Y.B. Gao, Y.J. Ma, J.J. Chen, B. Gan, Mater. Sci. Eng. A 823 (2021) 141739.
[53]	Y.B. Gao, Y.T. Ding, J.J. Chen, J.Y. Xu, Y.J. Ma, X.M. Wang, Mater. Sci. Eng. A 767 (2019) 138361.
[54]	Z.J. Wang, Q.J. Li, Y. Li, L.C. Huang, L. Lu, M. Dao, J. Li, E. Ma, S. Suresh, Z.W. Shan, Nature Commun. 8 (2017) 1108. DOI URL