Multi-physical Field Simulation for Quasi-in-situ Evolution of Porosity and Microstructure in WADED 2024 Aluminum Alloy

作者：Yubin Zhou, Yuan Zhao, Zewu Qi, Baoqiang Cong, Hui Li, Zhijun Wang, Jintao Ding, Chaofang Dong, Haibo Wang, Bojin Qi · 发表于：Chinese Journal of Mechanical Engineering · 年份：2026 · DOI：10.1016/j.cjme.2026.100300 · 被引用次数：1 · 研究领域：Additive Manufacturing Materials and Processes、Aluminum Alloy Microstructure Properties、High Entropy Alloys Studies

The wire arc directed energy deposited (WADED) 2024 aluminum alloy has significant application potential in in-situ repairing and additive manufacturing. In this circumstance, the additive deposits and substrate need to be used as a whole part. However, the internal defects and heterogeneous microstructure in transition layers deteriorate the WADED component properties. In this paper, the quasi-in-situ porosity and microstructure evolution of transition layers in WADED 2024 aluminum alloy was innovatively revealed. The computational fluid dynamics model was used to illustrate molten pool behaviors in WADED process. The regional pore aggregation in inter-layer zone (ITZ) was optimized with layer depositing due to the improved velocity magnitude for bubble escape. Heat accumulation affected the pore evolution, which led to the micropore precipitation and pore gathering and growing. The microstructure displayed columnar dendritic grains(CDG) and equiaxed grains (EG) mixing in inner-layer zone (INZ) while coarse EG in ITZ. The CDG fraction in each layer decreased with layers increasing due to the heat accumulation. The microhardness fluctuation was reduced with layers accumulating. The stable layers exhibited lower porosity of 0.158% and relatively homogeneous microstructure with few CDG. The component showed the ultimate tensile strength of 249.62 MPa, yield strength of 145.71 MPa, and elongation of 4.03% with excellent isotropy. This research innovatively illustrate molten pool...