Refinement of the grain structure of additive manufactured titanium alloys via epitaxial recrystallization enabled by rapid heat treatment

SCRIPTA MATERIALIA

卷:180

Article

Zou, Zhiyi¹  Simonelli, Marco¹  Katrib, Juliano²  Dimitrakis, Georgios³  Hague, Richard¹ 

[1] Univ Nottingham, Ctr Addit Mfg, Nottingham NG8 1BB, England

[2] Univ Nottingham, Adv Mat Res Grp, Nottingham NG8 1BB, England

[3] George Green Inst, Electromagnet Res Grp, Nottingham NG8 1BB, England

关键词: Additive manufacturing;    Titanium alloys;    Epitaxial recrystallization;    Rapid heat treatment;   

DOI  :  10.1016/j.scriptamat.2020.01.027

来源: Elsevier

【 摘 要 】

The coarse prior-beta grain structure in titanium alloys produced by additive manufacturing is associated to mechanical anisotropy and limited fatigue life. Here we report a novel methodology to refine such structure by rapid heat treatment of Ti-6Al-4V produced by laser powder-bed fusion. The refinement was analysed using high-temperature EBSD that showed, for the first time, how high angle boundary beta grains nucleated and grew with quasi-equiaxed morphology by epitaxial recrystallization. These findings show the potential for such heating regime to be applied to control grain size, morphology and distribution in a wider category of structural alloys produced by additive manufacturing. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd.

【 授权许可】

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