Understanding the refinement of grains in laser surface remelted Al-Cu alloys

SCRIPTA MATERIALIA

卷:178

Article

Patel, M. N.¹  Qiu, D.¹  Wang, G.²  Gibson, M. A.³  Prasad, A.²  StJohn, D. H.²  Easton, M. A.¹ 

[1] RMIT Univ, Sch Engn, Ctr Addit Mfg, Melbourne, Vic, Australia

[2] Univ Queensland, Sch Mech & Min Engn, Ctr Adv Mat Proc & Mfg, Brisbane, Qld, Australia

[3] CSIRO Mfg, Clayton, Vic, Australia

关键词: Aluminium alloys;    Grain refining;    Rapid solidification;    Solidification microstructure;    Nucleation free zone;   

DOI  :  10.1016/j.scriptamat.2019.12.020

来源: Elsevier

【 摘 要 】

The coarse-grained microstructure of laser surface remelted (LSR) Al-x wt.%Cu (x = 2, 5 & 7) is significantly refined by Al-3Ti-1B grain refiner. Epitaxial columnar grain growth at the melt pool boundary is suppressed. A reduction in grain size of about 80% is achieved and more than 25% of added TiB2 particles appear to be activated compared to less than 0.1% being activated during casting. The increased nucleation rate is explained in terms of an increase in thermal undercooling, activating a larger number of nucleants of lower potencies, and a reduction in the size of the nucleation free zone. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free