Abstract Eliminating defects related to molten pool geometry such as lack of fusion and keyhole effects, is an urgent issue in selective laser melting (SLM). A practical and effective method for predicting molten pool geometry becomes necessary to optimize process conditions and upgrade printing quality. In this study, a novel analytical model predicting molten pool geometry of SLM is proposed. The key of the model is to establish a heat balance within the front part of the molten pool based on a few assumptions supported by previous experimental and simulation discoveries. Compared with previous analytical models, the new model considers the specific molten pool configuration under the mutual action of recoil pressure and flow of melted metal. Experiments and numerical simulations of single-track SLM are carried out to validate analytical calculations. The results show good consistency when the input energy density is in the medium range. Correlations between the analytical predicted molten pool geometry and the defect thresholds of the inadequate fusion and the keyhole transition are investigated. The potential of the analytical model to rapidly predict molten pool cross-section geometry and determining the process window is demonstrated as well.

中文翻译：

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用于快速预测选择性激光熔化 (SLM) 熔池几何形状的分析模型

摘要 消除与熔池几何形状相关的缺陷，如未熔合和小孔效应，是选择性激光熔化 (SLM) 中的一个紧迫问题。一种用于预测熔池几何形状的实用且有效的方法对于优化工艺条件和提升印刷质量变得必要。在这项研究中，提出了一种预测 SLM 熔池几何形状的新型分析模型。该模型的关键是基于先前实验和模拟发现所支持的一些假设，在熔池前部建立热平衡。与以前的分析模型相比，新模型考虑了在反冲压力和熔融金属流动的相互作用下的特定熔池配置。进行了单轨 SLM 的实验和数值模拟，以验证分析计算。当输入能量密度在中等范围内时，结果显示出良好的一致性。研究了分析预测的熔池几何形状与不充分融合和小孔过渡的缺陷阈值之间的相关性。分析模型在快速预测熔池横截面几何形状和确定工艺窗口方面的潜力也得到了证明。