Characterization of powder bed selective laser sintering for multi-material additive manufacturing of Ni and Cu

Selective laser melting (SLM) is an additive manufacturing (AM) technology capable of producing fully dense, high strength parts with complex geometries. However, its application is currently limited to single-material components, restricting the potential for individual user functional customization for each part, which would be advantageous across many industries. Much effort is being undertaken to develop nozzle-based powder deposition mechanisms to enable multi-material production in SLM, which would enable further design complexity and precise material-property matching. Current multi-material deposition systems face significant challenges, including geometrical inaccuracies and material cross-contamination, which must be addressed to enhance the development of a feasible multi-material SLM system. This paper presents a vibration-induced nozzle powder deposition and an angled-leveling blade mechanism that addresses these key limitations. The system successfully demonstrates full deposition of a uniform and leveled powder bed comprising nickel and copper, thereby significantly reducing material contamination. The results showed that blade translation speed was less impactful than the blade angle on material contamination. A more complex, multi-layer geometry was also developed, but magnetism issues in the nickel powder compounded significantly when moving to multiple layers, therefore it was substituted with 316L SS powder to resume the study. Potential strategies are presented but are not investigated in this study. This development offers a promising step toward the broader adoption of multi-material additive manufacturing (MMAM) in SLM, improving the outlook on future developments where users can produce functional, application-tailored AM parts.

选择性激光熔化（Selective Laser Melting, SLM）是一种增材制造（Additive Manufacturing, AM）技术，可制备致密度高、力学性能优异且几何结构复杂的高性能构件。然而目前该技术的应用仅局限于单材质构件，这极大限制了针对每件构件开展用户个性化功能定制的潜力，而此类定制在诸多行业中均具备显著应用价值。当前学界与工业界已投入大量精力研发基于喷嘴的粉末沉积机构，以实现SLM工艺中的多材质生产，此举可进一步拓展设计复杂度并实现精准的材料性能匹配。当前的多材质沉积系统面临诸多严峻挑战，包括几何精度不足与材料交叉污染，若要推进实用化多材质SLM系统的研发，这些问题均需得到有效解决。本文提出了一种振动诱导式喷嘴粉末沉积与斜角整平刮刀机构，可针对性解决上述关键局限。该系统成功实现了由镍与铜组成的均匀平整粉末床的完整沉积，大幅降低了材料污染风险。研究结果表明，相较于刮刀平移速度，刮刀角度对材料污染的影响更为显著。研究团队还开发了更为复杂的多层几何结构，但在制备多层结构时，镍粉末的磁性问题显著加剧，因此改用316L不锈钢（316L Stainless Steel, 316L SS）粉末以继续本研究。本文提出了若干潜在优化策略，但未在本研究中展开验证与探讨。该项研究成果为SLM工艺中多材质增材制造（Multi-Material Additive Manufacturing, MMAM）的大规模应用迈出了极具前景的一步，为未来用户可制备适配应用场景的功能性定制化增材制造构件的发展前景提供了有力支撑。