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UCL Study Reveals How Substrate Microstructure Influences Defect Formation in LPBF of Aluminum Alloys
2026-05-08
A joint research team at University College London systematically investigated the influence of substrate microstructure on defect formation during laser powder bed fusion of aluminum alloys. Using a high-performance Al-Ni-Ce-Mn-Fe alloy (PA1) specially designed for additive manufacturing, single-track printing experiments were conducted on as-cast PA1 and rolled Al6061 substrates, tracked by high-speed synchrotron X-ray imaging. Results showed that large columnar intermetallic compounds in the as-cast PA1 substrate strongly induced defects during the initial printed layers, but this effect diminished as microstructure homogenized with increasing layer count. The study also identified a new defect type—"intermetallic-induced porosity"—originating from the interaction between laser keyholes and pre-existing intermetallic compounds in the substrate. These findings offer direct reference value for verifying powder batch consistency and the adaptability of consumable process windows.
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伦敦大学学院揭示基板微观结构对铝合金LPBF缺陷形成的影响
伦敦大学学院的联合研究团队系统研究了激光粉末床熔融铝合金过程中基板微观结构对缺陷形成的影响。该研究采用增材制造专用高性能Al-Ni-Ce-Mn-Fe合金（PA1），在铸态PA1和轧制Al6061基板上进行单道打印实验并进行高速同步辐射X射线成像跟踪。结果表明，铸态PA1基板中存在大尺寸柱状金属间化合物，在打印初始层时会强烈诱导缺陷产生，随着打印层数增加微观结构趋于均匀化，这一影响逐渐衰减。研究还发现一种新缺陷类型——“金属间化合物诱导气孔”，来源于激光小孔与基板中原有金属间化合物的相互作用。这项发现对验证粉末批次一致性及耗材工艺窗口的适应性具有直接参考价值。