Understanding the enhanced ductility of Mg-Gd with Ca and Zn microalloying by slip trace analysis

doi:10.1016/j.jmst.2021.02.070

Abstract

Abstract:

This research studied the mechanisms of Ca and Zn microalloying on the enhancement of ductility of extruded Mg-Gd sheet by combing electron backscattered diffraction and slip trace analysis. The ductility and microstructure of extruded Mg-0.6Gd and Mg-0.6Gd-0.3Ca-0.2Zn (wt%) sheets were investigated. Basal slip was the main deformation mode under investigation. Ca and Zn microalloying increased the frequency of grain boundaries (GBs) with misorientation angles (θs) < 35°, promoted slip transfer across GBs and restricted the basal slip localization. In addition, there were a higher number of GB cracks homogeneously distributed in the Mg-0.6Gd sheet than in the Mg-0.6Gd-0.3Ca-0.2Zn sheet, attributed to the increased cohesion of GBs. The enhancement of basal slip, the suppression of slip localization and the suppression of GB cracking were contributed to the increased ductility for Mg-0.6Gd-0.3Ca-0.2Zn sheet.

Key words: Mg-Gd, Ca-Zn microalloying, Slip trace, Cracking, Ductility

Jun Zhao, Bin Jiang, Yuan Yuan, Qinghang Wang, Ming Yuan, Aitao Tang, Guangsheng Huang, Dingfei Zhang, Fusheng Pan. Understanding the enhanced ductility of Mg-Gd with Ca and Zn microalloying by slip trace analysis[J]. J. Mater. Sci. Technol., 2021, 95: 20-28.

Figures/Tables 13

Table 1 Chemical compositions of the alloys (wt%).

Alloy	Mg	Gd	Ca	Zn
Mg-0.6Gd	Bal.	0.55	-	-
Mg-0.6Gd-0.3Ca-0.2Zn	Bal.	0.63	0.26	0.24

Fig. 1. XRD spectra of extruded sheets: (a) Mg-0.6Gd and (b) Mg-0.6Gd-0.3Ca-0.2Zn.

Fig. 2. SEM micrographs of the extruded sheets: (a) Mg-0.6Gd and (b) Mg-0.6Gd-0.3Ca-0.2Zn. The EDS results of the secondary phases are inserted in the SEM micrographs.

Fig. 3. IPF maps, (0001) pole figures and the Schmid factor for basal slip distributions (presuming a tensile stress along the ED) of the extruded sheets: (a, c, e) Mg-0.6Gd and (b, d, f) Mg-0.6Gd-0.3Ca-0.2Zn.

Fig. 4. Correlated and uncorrelated misorientation distributions of extruded sheets: (a) Mg-0.6Gd and (b) Mg-0.6Gd-0.3Ca-0.2Zn.

Fig. 5. (a) Tensile true stress-strain curves and (b) strain hardening rate curves of extruded sheets.

Table 2 EF, YS, UTS and n of extruded sheets.

Sheet	EF (%)	YS (MPa)	UTS (MPa)	n
Mg-0.6Gd	19	78	195	0.29
Mg-0.6Gd-0.3Ca-0.2Zn	26	82	231	0.31

Fig. 6. Frequency of basal and non-basal slip traces of extruded sheets after a strain of 10%.

Fig. 7. Orientations of grains with different slip traces and the corresponding Schmid factor distribution of the extruded sheets: (a, b) Mg-0.6Gd and (c, d) Mg-0.6Gd-0.3Ca-0.2Zn.

Fig. 8. IPF, band contrast maps and the orientations of grains with tensile twin of extruded sheets after a stain of 10% along the ED: a, c, e) Mg-0.6Gd and (b, d, f) Mg-0.6Gd-0.3Ca-0.2Zn.

Fig. 9. SEM images of grain boundary cracks in (a-c) Mg-0.6Gd and (d-f) Mg-0.6Gd-0.3Ca-0.2Zn sheets after a strain of 10%, and (g-i) Mg-0.6Gd-0.3Ca-0.2Zn sheet after a strain of 15%.

Fig. 10. SEM maps of visible slip traces and corresponding IPF maps in (a, b) Mg-0.6Gd and in (c, d) Mg-0.6Gd-0.3Ca-0.2Zn after 10% strain.

Fig. 11. (a) BF-STEM image, (b) corresponding HAADF-STEM image from an extruded Mg-0.6Gd-0.3Ca-0.2Zn sheet, (c) EDX line scan indicated black arrow across the grain boundary in Fig. 10b and EDX mapping showing (d) Gd solute segregation, (e) Ca solute segregation and (f) Zn solute segregation.

References 53

[1]	Q. Yang, B. Jiang, L. Wang, J. Dai, J. Zhang, F. Pan, J. Alloys Compd. 814 (2020) 152278. DOI URL
[2]	T. Xu, Y. Yan, X. Peng, J. Song, F. Pan, J. Magnes. Alloy. 5 (2019) 536-544.
[3]	Q. Wang, Y. Song, B. Jiang, J. Fu, A. Tang, H. Sheng, J. Song, D. Zhang, Z. Jiang, G. Huang, F. Pan, Mater. Sci. Eng. A 769 (2020) 138476. DOI URL
[4]	X. Liu, Z. Zhang, W. Hu, Q. Le, L. Bao, J. Cui, J. Mater. Sci. Technol. 32 (2016) 313-319.
[5]	Q. Li, G.J. Huang, X.D. Huang, S.W. Pan, C.L. Tan, Q. Liu, J. Magnes. Alloy 5 (2017) 166-172. DOI URL
[6]	H. Zhang, Y. Liu, J. Fan, H.J. Roven, W. Cheng, B. Xu, H. Dong, J. Alloys Compd. 615 (2014) 687-692. DOI URL
[7]	J. Xu, T. Yang, B. Jiang, J. Song, J. He, Q. Wang, Y. Chai, G. Huang, F. Pan, J. Alloys Compd. 762 (2018) 719-729. DOI URL
[8]	K.K. Alaneme, E.A. Okotete, J. Magnes. Alloy. 5 (2017) 460-475. DOI URL
[9]	H. Pan, R. Kang, J. Li, H. Xie, Z. Zeng, Q. Huang, C. Yang, Y. Ren, G. Qin, Acta Mater. 186 (2020) 278-290. DOI URL
[10]	Y. Wang, J. Peng, L. Zhong, J. Alloy. Compd. 744 (2018) 234-242. DOI URL
[11]	Q. Yang, B. Jiang, B. Song, Z. Yu, D. He, Y. Chai, J. Zhang, F. Pan, J. Magnes. Alloy. (2020) doi.org/10.1016/j.jma.2020.08.005. DOI
[12]	S.W. Lee, S.H. Kim, W.K. Jo, W.H. Hong, S.H. Park, J. Alloy. Compd. 791 (2019) 700-710. DOI URL
[13]	S. Sandlöbes, M. Friák, S. Zaefferer, A. Dick, S. Yi, D. Letzig, Z. Pei, L.F. Zhu, J. Neugebauer, D. Raabe, Acta Mater. 60 (2012) 3011-3021. DOI URL
[14]	W. Wu, L. Jin, F. Wang, J. Sun, Z. Zhang, W. Ding, J. Dong, Mater. Sci. Eng. A 582 (2013) 194-202. DOI URL
[15]	K.H. Kim, J.B. Jeon, N.J. Kim, B.J. Lee, Scr. Mater. 108 (2015) 104-108. DOI URL
[16]	Z. Wu, R. Ahmad, B. Yin, S. Sandlöbes, W.A. Curtin, Science 359 (2018) 447-452.
[17]	H.J. Bong, X. Hu, X. Sun, Y. Ren, Int. J. Plast. 113 (2019) 35-51. DOI URL
[18]	H.J. Bong, D. Yoo, D. Kim, Y.N. Kwon, J. Lee, J. Manuf. Process. 58 (2020) 775-786. DOI URL
[19]	H.J. Bong, J. Lee, X. Hu, X. Sun, M.-G. Lee, Int.J. Plast. 126 (2020) 102630.
[20]	S. Kim, J. Jung, B.S. You, S.H. Park, J. Alloy. Compd. 695 (2017) 344-350. DOI URL
[21]	F. Zhang, Y. Wang, Y. Duan, K. Wang, Y. Wang, W. Zhang, J. Hu, J. Alloys Compd. 788 (2019) 541-548. DOI URL
[22]	N. Stanford, D. Atwell, M.R. Barnett, Acta Mater. 58 (2010) 6773-6783. DOI URL
[23]	J. Zhao, B. Jiang, Y. Yuan, A. Tang, H. Sheng, T. Yang, G. Huang, D. Zhang, F. Pan, Mater. Sci. Eng. A 772 (2020) 138779. DOI URL
[24]	Y. Chai, C. He, B. Jiang, J. Fu, Z. Jiang, Q. Yang, H. Sheng, G. Huang, D. Zhang, F. Pan, J. Mater. Sci. Technol. 37 (2020) 26-37. DOI URL
[25]	H. Pan, C. Yang, Y. Yang, Y. Dai, D. Zhou, L. Chai, Q. Huang, Q. Yang, S. Liu, Y. Ren, G. Qin, Mater. Lett. 237 (2019) 65-68. DOI URL
[26]	B. Zhang, Y. Wang, L. Geng, C. Lu, Mater. Sci. Eng. A 539 (2012) 56-60. DOI URL
[27]	J. Hofstetter, S. Ruedi, I. Baumgartner, H. Kilian, B. Mingler, E. Povoden-Karad-eniz, S. Pogatscher, P.J. Uggowitzer, J.F. Loffler, Acta Mater 98 (2015) 423-432. DOI URL
[28]	Z.R. Zeng, Y.M. Zhu, S.W. Xu, M.Z. Bian, C.H.J. Davies, N. Birbilis, J.F. Nie, Acta Mater. 105 (2016) 479-494. DOI URL
[29]	B. Langelier, A.M. Nasiri, S.Y. Lee, M.A. Gharghouri, S. Esmaeili, Mater. Sci. Eng. A 620 (2015) 76-84. DOI URL
[30]	H. Ding, X. Shi, Y. Wang, G. Cheng, S. Kamado, Mater. Sci. Eng. A 645 (2015) 196-204. DOI URL
[31]	J. Zhao, J. Fu, B. Jiang, A. Tang, H. Sheng, T. Yang, G. Huang, D. Zhang, F. Pan, Met. Mater. Int. 645 (2019) 1-13.
[32]	M. Jahedi, B.A. McWilliams, P. Moy, M. Knezevic, Acta Mater 131 (2017) 221-232. DOI URL
[33]	W.X. Wu, L. Jin, J. Dong, W.J. Ding, Mater. Sci. Eng. A 593 (2014) 48-54. DOI URL
[34]	C.J. Boehlert, Z. Chen, I. Gutierrez-Urrutia, J. Llorca, M.T. Perez-Prado, Acta Mater. 60 (2012) 1889-1904. DOI URL
[35]	C.M. Cepeda-Jiménez, J.M. Molina-Aldareguia, M.T. Pérez-Prado, Acta Mater 88 (2015) 232-244. DOI URL
[36]	D.F. Shi, M.T. Pérez-Prado, C.M. Cepeda-Jiménez, Acta Mater. 180 (2019) 218-230. DOI
[37]	C.M. Cepeda-Jiménez, C. Prado-Martínez, M.T. Pérez-Prado, Acta Mater 145 (2018) 264-277. DOI URL
[38]	C.M. Cepeda-Jiménez, M. Castillo-Rodríguez, M.T. Pérez-Prado, Acta Mater 165 (2019) 164-176. DOI
[39]	C.M. Cepeda-Jiménez, J.M. Molina-Aldareguia, M.T. Pérez-Prado, Acta Mater 84 (2015) 443-456. DOI URL
[40]	T.R. Bieler, P. Eisenlohr, F. Roters, D. Kumar, D.E. Mason, M.A. Crimp, D. Raabe, Int. J. Plast. 25 (2009) 1655-1683. DOI URL
[41]	H. Li, D.E. Mason, T.R. Bieler, C.J. Boehlert, M.A. Crimp, Acta Mater 61 (2013) 7555-7567. DOI URL
[42]	C. Zhao, X. Chen, F. Pan, S. Gao, D. Zhao, X. Liu, Mater. Sci. Eng. A 713 (2018) 244-252. DOI URL
[43]	H. Paul, J.H. Driver, C. Maurice, Z. Jasienski, Mater. Sci. Eng. A 359 (2003) 178-191. DOI URL
[44]	S. Sandl €obes, I. Schestakow, S. Yi, S. Zaefferer, J. Chen, M. Friak, J. Neugebauer, D. Raabe, Mater. Sci. Forum 690 (2011) 202-205. DOI URL
[45]	J. Shi, M.A. Zikry, Int. J. Solids Struct. 46 (2009) 3914-3925. DOI URL
[46]	M. Yamaguchi, Metall. Mater. Trans. A 42 (2011) 319-329. DOI URL
[47]	M. Yamaguchi, M. Shiga, H. Kaburaki, Science 307 (2005) 393-397. PMID
[48]	J. Luo, H. Cheng, K.M. Asl, C.J. Kiely, M.P. Harmer, Science 333 (2011) 1730-1733. DOI URL
[49]	R. Schweinfest, A.T. Paxton, M.W. Finnis, Nature 432 (2004) 1008-1011. DOI URL
[50]	J. Zhao, B. Jiang, Y. Yuan, et al., Mater. Sci. Eng. A 104 (2020) 139344.
[51]	T. Hase, T. Ohtagaki, M. Yamaguchi, et al., Acta Mater. 104 (2016) 283-294. DOI URL
[52]	Y. Guo, Q. Luo, B. Liu, et al., Scr.Mater. 178 (2020) 422-427.
[53]	Q. Luo, Y. Guo, B. Liu, et al., in: J. Mater. Sci. Technol., 2020, pp. 171-190.