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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]
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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 

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References

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