Understanding the potential of solute trapping induced by rapid solidification in powder bed fusion additive manufacturing

作者：Yunhe Zhou, Yuchao Lei, Kenta Yamanaka, Yunping Li, Hao Wang, Hao Chen, Akihiko Chiba · 发表于：Journal of Materials Processing Technology · 年份：2025 · DOI：10.1016/j.jmatprotec.2025.118939 · 被引用次数：5 · 研究领域：Additive Manufacturing Materials and Processes、Additive Manufacturing and 3D Printing Technologies、Advanced materials and composites

Cu-Ag alloys are known for their exceptional combination of high strength and superior electrical and thermal conductivities. However, conventional manufacturing processes typically produce discontinuous Ag-rich precipitates that degrade performance. Through processing a Cu-5wt.%Ag alloy with electron beam powder bed fusion (PBF-EB), this study reveals the fundamental potential of solute trapping induced by rapid solidification, offering a new pathway to eliminate detrimental discontinuous precipitates. We demonstrate that high solidification rates, exceeding 1 m/s, can be achieved through process control and Cu's inherent high thermal conductivity. This induces significant solute trapping, resulting in a supersaturated Cu matrix during solidification and the precipitation of uniformly dispersed Ag-rich nanoparticles during in-process aging. Consequently, continuous precipitates form, eliminating the detrimental discontinuous precipitates typically persistent in traditional processes. Specifically, the PBF-EB samples exhibit relative densities of up to 98.78% and columnar grain structures with a strong <001> texture along building direction. Grain size varies with process parameters and building height, attributed to the variations in solidification conditions affected by heat accumulation and dissipation dynamics. Through altering solidification segregation, solidification rate can be used to govern the size and morphology of Ag-rich precipitates, thus affecting mechanical a...