Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-29T17:03:53.724Z Has data issue: false hasContentIssue false

Influence of direct rolling below β transus and annealing on microstructure and room temperature tensile properties of Ti–6Al–4V plates fabricated by electron-beam melting (EBM)

Published online by Cambridge University Press:  10 February 2015

Zheng Lv*
Affiliation:
Department of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
Xueping Ren
Affiliation:
Department of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
Hongliang Hou*
Affiliation:
Beijing Aeronautical Manufacturing Technology Research Institute (AVIC), Beijing 100024, People's Republic of China
*
a)Address all correspondence to these authors. e-mail: [email protected]
Get access

Abstract

Microstructure modification and room temperature tensile properties of Ti–6Al–4V plates fabricated by electron-beam melting (EBM) were investigated. Firstly, Ti–6Al–4V slabs were direct rolled at various preheat temperatures below β transus with various reductions, then the deformed samples were annealed at 800 °C for various soaking times. After rolling, the microstructure modification consists of elongation, bending, kinking, and rotation of α lamellae. Specimens rolled below 900 °C exhibited flow instability (local deformation bands). The mean aspect ratio of α lamellae was further decreased following annealing, and the fraction of α particles showed a relatively strong dependence on preceding rolling reduction. The variations of mean aspect ratio and spheroidization fraction with annealing time were rationalized on the basis of various processes during spheroidization. The mechanical properties of Ti–6Al–4V plates fabricated by EBM were significantly improved after rolling compared with as-cast Ti–6Al–4V plates. The following annealing of 1 h resulted in significant improvements on elongation without obvious loss of ultimate tensile strength (UTS).

Type
Articles
Copyright
Copyright © Materials Research Society 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Sheppard, T. and Norley, J.: Deformation characteristics of Ti-6Al-4V. Mater. Sci. Tech-Lond. 4, 10 (1988).Google Scholar
Huang, L., Kong, F., Chen, Y., and Xiao, S.: Microstructure and tensile properties of Ti-6Al-4V-0.1B alloys of direct rolling in the near β phase region. Mater. Sci. Eng., A 560, 140 (2013).Google Scholar
Salem, A.A., Glavicic, M.G., and Semiatin, S.L.: The effect of preheat temperature and inter-pass reheating on microstructure and texture evolution during hot rolling of Ti–6Al–4V. Mater. Sci. Eng., A 496(1), 169 (2008).Google Scholar
Kalinyuk, A.N., Trigub, N.P., Zamkov, V.N., Ivasishin, O.M., Markovsky, P.E., Teliovich, R.V., and Semiatin, S.L.: Microstructure, texture, and mechanical properties of electron-beam melted Ti-6Al-4V. Mater. Sci. Eng., A 346(1), 178 (2003).Google Scholar
Heinl, P., Müller, L., Körner, C., Singer, R., and Müller, F.: Cellular Ti-6Al-4V structures with interconnected macro porosity for bone implants fabricated by selective electron beam melting. Acta Biomater. 4(5), 1536 (2008).Google Scholar
Safdar, A. and Wei, L.Y.: Microstructures of electron beam melted (EBM) biomaterial Ti-6Al-4V. Mater. Res. Soc. Symp. Proc., Katti, K., Hellmich, C., Wegst, U.G.K., and Narayan, R. eds.; Boston, MA, Vol. 1132, 2008; p. 6.Google Scholar
Murr, L.E., Gaytan, S.M., Ramirez, D.A., Martinez, E., Hernandez, J., Amato, K.N., Shindo, P.W., Medina, F.R., and Wicker, R.B.: Metal fabrication by additive manufacturing using laser and electron beam melting technologies. J. Mater. Sci. Technol. 28(1), 1 (2012).Google Scholar
Wooten, J.R. and Dennies, D.P.: Microstructural evaluation of electron beam melted Ti-6Al-4V[J]. Microsc. Microanal. 14(S2), 616 (2008).Google Scholar
Semiatin, S.L., Seetharaman, V., and Weiss, I.: Flow behavior and globularization kinetics during hot working of Ti-6Al-4V with a colony alpha microstructure. Mater. Sci. Eng., A 263(2), 257 (1999).Google Scholar
Weiss, I., Froes, F.H., Eylon, D., and Welsch, G.E.: Modification of alpha morphology in Ti-6Al-4V by thermomechanical processing. Metall. Trans. A 17(11), 1935 (1986).Google Scholar
Ari-Gur, P. and Semiatin, S.L.: Evolution of microstructure, macrotexture and microtexture during hot rolling of Ti-6A1-4V. Mater. Sci. Eng., A 257(1), 118 (1998).CrossRefGoogle Scholar
Seshacharyulu, T., Medeiros, S.C., Frazier, W.G., and Prasad, Y.V.R.K.: Microstructural mechanisms during hot working of commercial grade Ti-6Al-4V with lamellar starting structure. Mater. Sci. Eng., A 325(1), 112 (2002).Google Scholar
Zherebtsov, S., Murzinova, M., Salishchev, G., and Semiatin, S.L.: Spheroidization of the lamellar microstructure in Ti-6Al-4V alloy during warm deformation and annealing. Acta Mater. 59(10), 4138 (2011).Google Scholar
Murty, S.V.S., Nayan, N., Kumar, P., Narayanan, P., Sharma, S.C., and George, K.: Microstructure–texture–mechanical properties relationship in multi-pass warm rolled Ti-6Al-4V Alloy. Mater. Sci. Eng., A 589, 174 (2014).Google Scholar
Bieler, T.R. and Semiatin, S.L.: The origins of heterogeneous deformation during primary hot working of Ti-6Al-4V. Int. J. Plast. 18(9), 1165 (2002).Google Scholar
Furuhara, T., Ogawa, T., and Maki, T.: Atomic structure of interphase boundary of a precipitate plate in α β Ti [sbnd] Cr alloy. Philos. Mag. Lett. 72(3), 175 (1995).Google Scholar
Sen, I., Tamirisakandala, S., Miracle, D.B., and Ramamurty, U.: Microstructural effects on the mechanical behavior of B-modified Ti–6Al–4V alloys. Acta Mater. 55(15), 4983 (2007).Google Scholar
Miller, R.M., Bieler, T.R., and Semiatin, S.L.: Flow softening during hot working of Ti-6Al-4V with a lamellar colony microstructure. Scr. Mater. 40(12), 1387 (1999).Google Scholar