Abstract This paper presents an appropriate method to significantly reduce the pore size of high porosity porous stainless steel 316L structures fabricated by laser powder-bed fusion (LPBF) utilizing pulse wave emission (PW). PW deliberately avoids full-melt and applies low energy conditions to achieve single layer sintered porous material with controlled characteristics. Experimental approaches on a lab-scale setup equipped with a pulsed fiber laser system were developed to investigate the effect of laser scan settings. Properties of low-energy laser single sintered layers are studied experimentally, and the influence of laser power and pulse duration is discussed. A layer of sintered porous material was characterized in terms of the pore size, layer thickness, porosity and thermal conductivity. The results show that sintered porous layers can be fabricated by effectively connecting metal powder in the powder bed similar to a sintering process or partial melting. The porosity of fabricated structures was 51%–61% and the average pore radius ranged between 22 and 29 μm. We found that the thermal conductivity of a single powder particle is 31.5% of the sintered layer value and the thermal conductivity of the sintered layer is 4.8% of its solid material.

中文翻译：

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低能量增材制造的多孔材料：单层制造和表征

摘要 本文提出了一种适当的方法来显着减小由激光粉末床融合（LPBF）利用脉冲波发射（PW）制造的高孔隙率多孔不锈钢316L结构的孔径。PW 特意避免完全熔化并应用低能量条件来实现具有受控特性的单层烧结多孔材料。开发了配备脉冲光纤激光系统的实验室规模设置的实验方法，以研究激光扫描设置的影响。实验研究了低能激光单烧结层的特性，讨论了激光功率和脉冲持续时间的影响。烧结多孔材料层的特征在于孔径、层厚度、孔隙率和热导率。结果表明，类似于烧结过程或部分熔化，通过在粉末床中有效连接金属粉末可以制造烧结多孔层。制造结构的孔隙率为 51%–61%，平均孔隙半径介于 22 和 29 μm 之间。我们发现单个粉末颗粒的热导率为烧结层值的 31.5%，烧结层的热导率为其固体材料的 4.8%。