A novel heterogeneous multi-wire indirect arc directed energy deposition for in-situ synthesis Al-Zn-Mg-Cu alloy: Process, microstructure and mechanical properties

作者：Liwei Wang, Tao Wu, Dianlong Wang, Zhimin Liang, Xiao Yang, Zhenzhen Peng, Ying Liu, Yongmei Liang, Zhi Zeng, J.P. Oliveira · 发表于：Additive manufacturing · 年份：2023 · DOI：10.1016/j.addma.2023.103639 · 被引用次数：83 · 研究领域：Aluminum Alloy Microstructure Properties、Additive Manufacturing Materials and Processes、Welding Techniques and Residual Stresses

Aiming to decouple the inherent relationship between mass transfer and heat transfer in traditional arc-based directed energy deposition, a novel heterogeneous multi-wire indirect arc directed energy deposition (DED) has been developed for in-situ synthesis of Al-Zn-Mg-Cu alloy components. Multi-wires (Al-Cu and Al-Mg) with a bypassing Zn wire have been used to replace the traditional homogeneous twin-wires. The process, microstructure and mechanical properties of the deposited Al-Zn-Mg-Cu alloy components obtained by multi-wire indirect arc DED were investigated. The results indicate that the wire feeding speed, current and angle between the two wires have a significant influence on the multi-wire indirect arc DED process. When the current was 200 A, the different wire feeding speeds could be used for both wires and the angle between them was 90°. The resulting indirect arc presented a ‘heart’ shape and allowed to obtain an Al-5.7Zn-3.4Mg-1.6Cu (wt%) alloy with a high deposition rate of 5.1 kg/h. The Al-5.7Zn-3.4Mg-1.6Cu alloy is mainly composed of α-Al, S (Al2CuMg), η (Mg (Al, Zn, Cu)2) and η′ phases. The composition and phases are in accordance with the 7xxx series aluminum alloys. The microstructure is dominated by columnar and equiaxed grains, and it has obvious periodic distribution along the building direction, which is related to the process thermal cycle. Fine second phases η′ are observed to precipitate during the manufacturing process. Furthermore, the average hard...