Formation and evolution of the interfacial structure in al/steel compound castings during solidification and heat treatment

JOURNAL OF ALLOYS AND COMPOUNDS

卷:849

Article

Bakke, Aina Opsal¹  Arnberg, Lars¹  Loland, Jan-Ove²  Jorgensen, Svein²  Kvinge, Jan²  Li, Yanjun¹ 

[1] Norwegian Univ Sci & Technol, Dept Mat Sci & Engn, Alfred Getz Vei 2, N-7034 Trondheim, Norway

[2] Aludyne Norway, Vollmonaveien 7, N-4550 Farsund, Norway

关键词: Metals and alloys;    Intermetallics;    Liquid-solid reactions;    Microstructure;   

DOI  :  10.1016/j.jallcom.2020.156685

来源: Elsevier

【 摘 要 】

In this work, Al7SiMg/steel compound castings were produced through a low-pressure die casting process. All steel inserts were galvanized, where half of them were flux-coated to further improve the wettability and remove interfacial oxide layers during casting. The reaction layer formed in the Al7SiMg/steel interface was examined using Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). In addition, Vickers Micro-hardness was measured across the interface. Results show that successful metallurgical bonding can be achieved between aluminum and galvanized steel, both with and without additional flux coating. A large fraction of intermetallic particles formed at the reaction layer, where ternary Al4.5FeSi particles were the dominating phase. The influence of T6 heat treatment (solution treatment at 540 degrees C, followed by artificial ageing) on the interfacial microstructure was also studied. After heat-treatment, the thickness of the interfacial layer increased significantly, due to the growth of beta-Al4.5FeSi and Al-Fe binary particles into the bulk of steel. Consequently, cracks formed and propagated through the inner binary intermetallic layer. Formation mechanisms of various intermetallic phases at the interface during solidification and heat treatment have been discussed. (C) 2020 The Authors. Published by Elsevier B.V.

【 授权许可】

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