Mixing of Spherical Solid and Nanoporous Copper Powders As Low-Reflectance Feedstock for Laser Powder Bed Fusion
Mixing of Spherical Solid and Nanoporous Copper Powders As Low-Reflectance Feedstock for Laser Powder Bed Fusion
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球形固体和纳米多孔铜粉的混合作为激光粉末床熔融的低反射率原料
DOI：
10.1115/msec2023-105092
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Azeredo, Bruno
中科院分区：
文献类型：
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作者：
Kublik, Natalya;Niauzorau, Stanislau;Azeredo, Bruno
微米多孔材料和纳米多孔材料由于其尺寸依赖性而引起了科学界的关注，所述尺寸依赖性包括但不限于高比表面积、表面扩散率、体扩散率和渗透性、催化活性和独特的光学性质。在这项工作中，球形纳米多孔铜（np-Cu）粉末，由于其纳米尺寸的孔隙度和低的Cu 2 O含量，显示半球总反射率为20%，这是显着低于其散装对应值为固体或熔融铜的约97%，在大多数商业激光粉末床融合（L-PBF）商业机器的波长。np-Cu粉末的低反射率具有用于L-PBF的潜力，以提高激光吸收，体积能量效率和这种增材制造工艺的产量。事实上，制备的仅含有5重量%的固体Cu粉末的混合物是优选的。np-Cu粉末的反射率比纯铜粉末低34.8%。Np-Cu粉末通过气体雾化CuAl合金的化学脱合金化以稳健且可扩展的方法制备，然后与纯铜粉末混合以制备混合原料。在此框架下，解聚策略的关键作用，以实现均匀性和流动性的np-Cu/Cu混合混合物通过颗粒成像，以确定团聚体的大小和组合物的眼睛在L-PBF获得高品质的打印进行评估。在np-Cu粉末制造中，在低表面张力流体中洗涤它们在其制造过程中维持最高程度的解聚，并且对于混合原料制备，在去合金化之前预混合Cu和CuAl产生最好的均匀性结果，具有最小尺寸的团聚体和良好的流动性。
Micro- and nanoporous materials have gathered attention from the scientific community due to their size dependent properties, including but not limited to high specific surface area, surface diffusivity, bulk diffusivity and permeability, catalytic activity, and distinct optical properties. In this work, spherical nanoporous copper (np-Cu) powders, due to their nanosized porosity and low Cu2O content, show hemispherical total reflectance of 20% which is significantly lower than its bulk counterpart value for solid or molten copper of approximately 97% at wavelengths of most commercial Laser Powder Bed Fusion (L-PBF) commercial machines. The low-reflectance of np-Cu powders has the potential to be used in L-PBF to improve laser absorption, volumetric energy efficiency, and throughput of this additive manufacturing process. In fact, a prepared mixture of solid Cu powders containing only 5 wt.% of np-Cu powders reflects 34.8 % less than pure copper powders as shown in this paper. Np-Cu powders are fabricated via chemical dealloying of gas atomized CuAl alloy in a robust and scalable approach, and then mixed with pure copper powders to prepare hybrid feedstocks. Under this framework, the crucial role of deglomeration strategies to achieve homogeneity and flowability of np-Cu/Cu hybrid mixtures are evaluated via particle imaging to determine agglomerate size and composition with an eye at obtaining a high-quality print in L-PBF. In np-Cu powders fabrication, washing them in low-surface tension fluids upholds the highest degree of deglomeration in their fabrication process, and for hybrid feedstocks preparation, pre-mixing Cu and CuAl prior to dealloying yields the best homogeneity results with smallest size of agglomerates and good flowability.