AI 中文总结
研究针对增材制造AlSi10Mg镜因LPBF产生孔隙问题，提出激光重熔策略，通过制造概念验证立方体和实际镜子评估该策略，虽概念验证可行，但要将优势转化到实际镜子还需优化LPBF和SPDT工艺。
AI 中文摘要
通过激光粉末床熔融（LPBF）制造的增材制造（AM）AlSi10Mg镜，能采用如晶格和有机结构等复杂几何形状，在保持机械刚度的同时实现高质量减轻。由于偏离最佳加工窗口，特别是激光能量输入和扫描策略，LPBF过程中可能形成导致光散射的微米级孔隙。本文提出一种旨在降低孔隙率的激光重熔策略，标准LPBF构建步骤与激光重熔过程自动交替，在此过程中先前沉积的材料被重熔。通过制造10毫米概念验证立方体对激光重熔进行评估。经过单点金刚石车削（SPDT）后，光学测量表征了表面粗糙度并识别了表面缺陷。性能最佳的AlSi10Mg重熔立方体在采样区域内无孔隙，平均表面粗糙度达到6.4纳米，与传统制造的RSA 6061对照立方体（5.8纳米）相当。受这些结果推动，使用LPBF和激光重熔制造了直径52毫米的AM二次夹层镜。这些镜子采用了优化的金刚石TPMS晶格，在考虑增材制造设计的同时实现了50%的质量减轻。与立方体研究不同，重熔镜在SPDT后的光学表面显示有残余孔隙，平均表面粗糙度为11.8纳米。这些结果表明，虽然概念验证证实了激光重熔在降低简单几何形状孔隙率方面的可行性，但需要优化LPBF和SPDT工艺，才能将激光重熔的优势转化为轻质AlSi10Mg增材制造镜。
英文摘要
Additively manufactured (AM) AlSi10Mg mirrors are fabricated through laser powder bed fusion (LPBF), allowing the use of complex geometries such as lattices and organic structures that enable high mass reduction while maintaining mechanical stiffness. Micron-sized pores that cause optical scatter may form during LPBF as a consequence of deviations from the optimal processing window, particularly from laser energy input and scan strategy. This work proposes a laser remelting strategy aimed at reducing porosity; standard LPBF build steps automatically alternate with laser remelting passes, where previously deposited material is remelted during fabrication. Laser remelting is evaluated through fabricating 10 mm proof-of-concept cubes. Following single point diamond turning (SPDT), optical measurements characterised surface roughness and identified surface artefacts. The best-performing AlSi10Mg remelted cube exhibited no pores within sampled regions and achieved 6.4 nm average surface roughness, comparable to a conventionally manufactured RSA 6061 control cube (5.8 nm). Driven by these results, AM 52 mm diameter secondary sandwich mirrors were manufactured using LPBF and laser remelting. These incorporate an optimised diamond TPMS lattice to achieve a 50% mass reduction while accommodating design for AM considerations. Unlike the cube study, the optical surface of the remelted mirror after SPDT exhibited residual porosity and 11.8 nm average surface roughness. These results show that while the proof-of-concept confirmed the viability of laser remelting in reducing porosity within simple geometries, optimisation of the LPBF and SPDT processes are required to translate the benefits of laser remelting to lightweight AlSi10Mg AM mirrors.
Comments37 pages, 37 figures, submitted to SPIE Astronomical Telescopes & Instrumentation 2026, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation VII (Conference 14154, Paper 199)
