Revealing hot tearing mechanism for an additively manufactured high-entropy alloy via selective laser melting

SCRIPTA MATERIALIA

卷:168

Article

Sun, Z.¹  Tan, X. P.¹  Descoins, M.²  Mangelinck, D.²  Tor, S. B.^1,3  Lim, C. S.³ 

[1] Nanyang Technol Univ, Sch Mech & Aerosp Engn, Singapore Ctr 3D Printing, 50 Nanyang Ave, Singapore 639798, Singapore

[2] Univ Aix Marseille, CNRS, UMR 7334, IM2NP, F-13397 Marseille 20, France

[3] Nanyang Technol Univ, Sch Mech & Aerosp Engn, 50 Nanyang Ave, Singapore 639798, Singapore

关键词: Additive manufacturing;    High-entropy alloy;    Laser deposition;    Solidification;    Hot cracking;   

DOI  :  10.1016/j.scriptamat.2019.04.036

来源: Elsevier

【 摘 要 】

Hot tearing mechanisms of a high-entropy alloy CoCrFeNi additively manufactured by selective laser melting have been investigated. Intergranular hot cracks are present regardless of various parameters used, suggesting poor laser-based printability for the alloy. Elemental segregation does not exist at the grain boundary that favours the hot cracking. We find that severe residual stress induced by the large grain size is the root cause for the intergranular cracking. The classic Rappaz-Drezet-Gremaud model is used to predict the characteristic depression pressure limit beyond which hot tearing will occur for the selective laser melting of metals and alloys. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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