Analysis of crystallographic orientation and morphology of microstructure during hot working for an alpha/beta titanium alloy

doi:10.1016/j.jmst.2020.06.002

Abstract

Abstract:

This work focuses on analysis of microstructure morphology and crystallographic orientation for Ti-17 alloy during hot working. The results show that alpha phase and beta phase influence each other and there is a coordinate deformation between them. The non-uniform deformation is observed under small deformation conditions. The observing area can be divided into small deformation zone (area L) and large deformation zone (area H). Both alpha and beta phases remain the initial morphology, and they have better capability of coordinate deformation in area L, while coordinate capability is weak in area H in which alpha phase is globularized. Correspondingly, the Burgers orientation relations are well preserved in area L, but the orientation relations are more or less destroyed in area H. Dynamic recovery is the main mechanism of beta phase evolution when height reduction is lower. By contrast, the continuous dynamic recrystallization (CDRX) of beta phase gradually dominates the deformation pattern as the deformation increases. An uniformly globularized alpha structure is obtained under large deformation condition. The unsynchronized rotation of alpha phase around <11-20> pole occurs during deformation, which leads to the uniform crystal structure inside the same alpha lamellae. This process is an important step of globularization of the lamellar structure.

Key words: Ti-17 alloy, Hot working, Microstructure evolution, Crystallographic orientation

panelJianwei Xu, Weidong Zeng, Dadi Zhou, Wei Chen, Shengtong He, Xiaoyong Zhang. Analysis of crystallographic orientation and morphology of microstructure during hot working for an alpha/beta titanium alloy[J]. J. Mater. Sci. Technol., 2020, 59: 1-13.

Figures/Tables 15

Fig. 1. Microstructure of the as-received Ti-17 alloy.

Fig. 2. Sampling point of the sample.

Fig. 3. Characteristics of crystal orientation of the as-received material (a) band contrast, (b) inverse pole figure of alpha phase and (c) inverse pole figure of beta phase.

Fig. 4. Pole figures of as-received Ti-17 alloy: (a) alpha phase and (b) beta phase.

Fig. 5. Microstructure morphology for Ti-17 alloy deformed to different height reductions: (a) 20 %, (b) 40 %, (c) 60 % and (d) 80 %.

Fig. 6. TEM morphology for Ti-17 alloy deformed to height reductions of (a) 20 %, (b) 40 %, (c) 60 % and (d) 80 %.

Fig. 7. The EBSD results for material deformed to height reductions of 20 %: (a) Phase diagram and (b) inverse pole figure.

Fig. 8. Pole figures for (a) area H and (b) area L.

Fig. 9. The EBSD analysis of the selected grains for material deformed to height reduction of 20 %.

Fig. 10. The EBSD results for material deformed to height reductions of 60 %: (a) phase diagram, (b) inverse pole figure of alpha phase and (c) inverse pole figure of beta phase.

Fig. 11. Pole figures for material deformed to height reductions of 60 %: (a) alpha phase and (b) beta phase.

Fig. 12. Recrystallization diagrams of beta phase for material deformed to height reductions of (a) 20 % and (b) 60 %.

Fig. 13. Pole figures of the labeled alpha phase in Fig. 9.

Fig. 14. Schmid factor maps of (a) <11-20> direction of alpha phase and (b) <111> direction of beta phase for material deformed to height reductions of 20 %.

Fig. 15. Schmid factor maps of (a) <11-20> direction of alpha phase and (b) <111> direction of beta phase for material deformed to height reductions of 60 %.

References 29

[1]	S.L. Semiatin, T.R. Bieler, Acta Mater. 49 (2001) 3565-3573.
[2]	P.F. Gao, M.W. Fu, M. Zhan, et al., J.Mater. Sci. Technol. 39 (2020) 56-73.
[3]	J.W. Xu, W.D. Zeng, H.Y. Ma, et al., J.Alloys Comp. 736 (2018) 99-107.
[4]	J.W. Xu, W.D. Zeng, X.Y. Zhang, et al., J.Alloys Comp. 788 (2019) 110-117.
[5]	R. Shi, V. Dixit, G.B. Viswanathan, et al., Acta Mater. 102 (2016) 197-211.
[6]	Z.B. Zhao, Q.J. Wang, Q.M. Hu, et al., Acta Mater. 126 (2017) 372-382.
[7]	Z.B. Zhao, Q.J. Wang, J.R. Liu, et al., Acta Mater. 131 (2017) 305-314.
[8]	G.C. Obasi, S. Birosca, J. Quinta da Fonseca, Acta Mater. 60 (2012) 1048-1058.
[9]	T. Karthikeyan, A. Dasgupta, R. Khatirkar, et al., Mater. Sci. Eng. A 528 (2010) 549-558.
[10]	D.G. Leo Prakash, P. Honniball, D. Rugg, et al., Acta Mater. 61 (2013) 3200-3213.
[11]	G.C. Obasi, J. Quinta da Fonseca, D. Rugg, et al., Mater. Sci. Eng. A 576 (2013) 272-279.
[12]	S. Balachandran, A. Kashiwar, A. Choudhury, et al., Acta Mater. 106 (2016) 374-387.
[13]	F. Sun, J.Y. Zhang, M. Marteleur, et al., Acta Mater. 61 (2013) 6406-6417.
[14]	Q.Y. Zhao, F. Yang, R. Torrens, L. Bolzoni, Mater. Design 169 (2019) 10768.
[15]	Q.Y. Zhao, F. Yang, R. Torrens, L. Bolzoni, Mater. Charact. 149 (2019) 226-238.
[16]	S. Balachandran, S. Kumar, D. Banerjee, Acta Mater. 131 (2017) 423-434.
[17]	S. Mironov, M. Murzinova, S. Zherebtsov, et al., Acta Mater. 57 (2009) 2470-2481.
[18]	J.W. Xu, W.D. Zeng, D.D. Zhou, et al., J.Alloys Comp. 767 (2018) 285-292.
[19]	S.L. Semiatin, V. Seetharaman, I. Weiss, Mater. Sci. Eng., A 263 (1999) 257-271.
[20]	C.B. Wu, H. Yang, X.G. Fan, et al., Trans. Nonferrous Met. Soc. China 21 (2011) 1963-1969.
[21]	C.H. Park, J.W. Won, J.W. Park, S.L. Semiatin, C.S. Lee, Metall. Mater. Trans. A 43 (2012) 977-985.
[22]	X. Ma, W.D. Zeng, F. Tian, Y.G. Zhou, Mater. Sci. Eng. A 548 (2012) 6-11.
[23]	H.W. Song, S.H. Zhang, M. Cheng, J. Alloys Comp. 480 (2009) 922-927.
[24]	J.W. Xu, W.D. Zeng, Z.Q. Jia, et al., J.Alloys Comp. 603 (2014) 239-247.
[25]	J.W. Xu, W.D. Zeng, Z.Q. Jia, et al., J.Mater. Eng. Perform. 25 (2016) 734-743.
[26]	S. Fréour, D. Gloaguen, M. Franc¸ ois, et al., Scripta Mater. 54 (2006) 1475-1478.
[27]	J.C. Williams, Mater. Sci. Eng. A 263 (1999) 107-111.
[28]	J.W. Xu, W.D. Zeng, H.Y. Ma, et al., J.Alloys Comp. 736 (2018) 99-107.
[29]	L. Li, J. Luo, J.J. Yan, et al., J.Alloys. Compd. 622 (2015) 174-183.