The high optical reflectance of Cu at near-infrared wavelengths narrows the process window to fabricate Cu parts by laser powder bed fusion (LPBF). Coating powders with optically absorptive materials has been investigated to improve processability and enhance part properties. However, given the intense heat localization and thin coating layers relative to the powder, the mechanisms of thin film coating interaction in LPBF remain unclear, despite recent work showing the importance of the near-track environment in deposition behavior. In this study, optically absorptive Zn-coated Cu powders were prepared by physical vapor deposition and characterized. Single LPBF tracks were fabricated to elucidate material incorporation phenomena influenced by the volatile Zn coating. It is shown that Zn-coated powder enhances accretion at fastest effective scan speed tested (100 mm/s), where mean track volumes are increased from 0.72 ± 0.05 mm³ (as-received) to 0.91 ± 0.01 mm³ (Zn-coated). This has been correlated to the stronger vapor jet from the volatile Zn-coating, which denudes the surrounding powder bed. This exhausts the powder bed at slower effective scan speeds, causing instability and balling when compared to the as-received powder. It is shown that Zn is localized at the track surface and is undetectable in the track bulk, indicating Zn vaporization on interaction with the incident beam. Zn present mainly occurs through secondary deposition mechanisms like spatter and condensation, rather than in-process alloying. Coating powder feedstocks for use in LPBF therefore affects composition, laser beam absorptivity, and the near-track vapor environment that is known to influence material incorporation behavior.

Cu 在近红外波长的高光学反射率缩小了通过激光粉末床融合 (LPBF) 制造 Cu 部件的工艺窗口。已经研究了具有光学吸收材料的涂层粉末以改善可加工性和增强零件性能。然而，鉴于相对于粉末的强烈热局部化和薄涂层，LPBF 中薄膜涂层相互作用的机制仍不清楚，尽管最近的工作表明近径环境在沉积行为中的重要性。在这项研究中，通过物理气相沉积制备了光学吸收性锌包覆铜粉并对其进行了表征。制造单个 LPBF 轨迹以阐明受挥发性 Zn 涂层影响的材料掺入现象。³（原样）至 0.91 ± 0.01 mm ³（镀锌）。这与来自挥发性锌涂层的更强蒸汽射流有关，这会破坏周围的粉末床。这会以较慢的有效扫描速度耗尽粉末床，与接收的粉末相比，会导致不稳定和成球。结果表明，Zn 位于轨道表面，在轨道体中无法检测到，这表明 Zn 在与入射光束相互作用时会蒸发。Zn 的存在主要通过二次沉积机制（如飞溅和冷凝）发生，而不是通过过程中的合金化发生。因此，用于 LPBF 的涂层粉末原料会影响成分、激光束吸收率和已知会影响材料掺入行为的近径蒸汽环境。