Abstract The low laser absorptivity and high thermal conductivity of Al are the foremost concerns when developing Al matrix composites (AMCs) through laser powder bed fusion (L-PBF) process. In this study, we demonstrated an example of improving the 3D-printability of AMCs by means of powder surface modification. Flexible graphene oxide (GO) sheets were carefully coated onto the surface of AlSi10Mg powders under electrostatic self-assembly via a hetero-agglomeration process. In addition to maintaining a shape and particle size similar to the initial metallic powders, the GO-coated AlSi10Mg powders exhibited enhanced laser absorptivity and decreased thermal conductivity, beneficial to their fusion. Under high-energy irradiation, the GO sheets were partially transformed to Al4C3 nanorods individually distributed in the matrix, while the un-reacted parts floated within molten pools under buoyancy, forming an in-situ carbon layer tightly deposited on the surface of the composite build. This work may provide significant guidance for the design and production of high-performance AMCs with advanced architectures for practical applications.

中文翻译：

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I激光增材制造氧化石墨烯/AlSi10Mg复合材料的显微结构和力学性能

摘要 在通过激光粉末床熔融（L-PBF）工艺开发铝基复合材料（AMC）时，铝的低激光吸收率和高热导率是最重要的问题。在这项研究中，我们展示了一个通过粉末表面改性提高 AMC 3D 可打印性的例子。在静电自组装下，通过异质团聚工艺将柔性氧化石墨烯 (GO) 片小心地涂覆在 AlSi10Mg 粉末的表面上。除了保持与初始金属粉末相似的形状和粒径外，GO 涂层的 AlSi10Mg 粉末还表现出增强的激光吸收率和降低的热导率，有利于它们的融合。在高能照射下，GO 片材部分转变为单独分布在基体中的 Al4C3 纳米棒，而未反应的部分在浮力作用下漂浮在熔池中，在复合材料表面形成紧密沉积的原位碳层。这项工作可能为设计和生产具有用于实际应用的先进架构的高性能 AMC 提供重要指导。