Abstract Recent advances in selective laser melting (SLM) 3D printing technology allows additive manufacture of lower hybrid current drive (LHCD) RF launchers from a new material, Glenn Research Copper 84 (GRCop-84), a Cr2Nb (8 at. % Cr, 4 at. % Nb) precipitation hardened alloy, in configurations unachievable with conventional machining. Rough surfaces in additive manufactured components are a limiting factor in RF structures. Surface roughness increases RF losses and impedes conditioning by trapping gas and contaminants that induce arcing by evolving from the surface at high power. SLM printed GRCop-84 is post-processed with mass finishing to reduce surface roughness. Wet blasting, vibratory finishing, and chemical etching remove adhered powder grains from SLM printed GRCop-84. Profilometry and scanning electron microscopy were used to quantify resulting surface quality. Chemical etching is examined to remove zinc contamination from wire electrical discharge machining slag prior to vacuum use. Etch rates in SLM printed GRCop-84 are anisotropic, and etch times should be limited to prevent pitting corresponding to the laser hatch pattern. Vibratory mass finishing and mechanical polishing produced surfaces suitable for low RF loss. Use of chemo-mechanical finishing is recommended for the interior of SLM printed structures.

中文翻译：

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用于增材制造的低混合电流驱动发射器的选择性激光熔化 GRCop-84 铜的表面粗糙度和精加工技术

摘要选择性激光熔化 (SLM) 3D 打印技术的最新进展允许使用新材料 Glenn Research Copper 84 (GRCop-84)（一种 Cr2Nb（8 at.% Cr， 4 at. % Nb) 沉淀硬化合金，采用传统加工无法实现的配置。增材制造组件中的粗糙表面是射频结构的限制因素。表面粗糙度会增加射频损耗，并通过捕获气体和污染物来阻碍调节，这些气体和污染物会在高功率下从表面产生电弧。 SLM 打印的 GRCop-84 经过大规模精加工后处理，以降低表面粗糙度。湿喷砂、振动精加工和化学蚀刻可去除 SLM 打印的 GRCop-84 上粘附的粉末颗粒。使用轮廓测定法和扫描电子显微镜来量化所得的表面质量。在真空使用之前，检查化学蚀刻以去除电火花线切割加工渣中的锌污染物。 SLM 打印的 GRCop-84 中的蚀刻速率是各向异性的，并且应限制蚀刻时间以防止与激光填充图案相对应的点蚀。振动质量精加工和机械抛光产生适合低射频损耗的表面。建议对 SLM 打印结构的内部使用化学机械精加工。