Abstract Three-dimensional finite element heat transfer simulations with new volumetric heat source are performed to estimate the size of the melt pool cross-section during Selective Laser Melting (SLM). The simulations are based on a new volumetric heat source which takes into account the effect of the powder size distribution on the propagation of the laser energy through the depth of the metal powder layer. In modeling the volumetric heat source, a modified sequential addition method is used to construct the metal powder layer with different powder particle sizes and the absorptivity profile along the depth of the powder layer is then calculated by means of Monte Carlo ray-tracing simulations. It is shown that the peak melt pool temperature obtained in the present simulations (3005 K) is in better agreement with the experimental value than that obtained in previous simulation studies. Furthermore, the peak temperature is lower than the evaporation point of the powder particle layer, and is hence consistent with the stable melt track reported in experimental studies. To further confirm the validity of the proposed finite element heat transfer model, the simulation results obtained for the contact width between the melt pool and the substrate and the width of the powder-consumed band are compared with the experimental results and simulation findings presented in the literature. Finally, simulations are performed to predict the stability condition of a single scan melt track in the SLM process. The prediction results are shown to be consistent with the experimental findings.

中文翻译：

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基于体积热源并考虑粉末尺寸的选择性激光熔化过程传热模拟

摘要 使用新的体积热源进行三维有限元传热模拟，以估计选择性激光熔化（SLM）过程中熔池横截面的尺寸。模拟基于新的体积热源，该热源考虑了粉末尺寸分布对激光能量通过金属粉末层深度传播的影响。在模拟体积热源时，使用改进的顺序添加方法构建具有不同粉末粒径的金属粉末层，然后通过蒙特卡罗射线追踪模拟计算沿粉末层深度的吸收率分布。结果表明，在本次模拟中获得的峰值熔池温度 (3005 K) 与实验值比在以前的模拟研究中获得的更吻合。此外，峰值温度低于粉末颗粒层的蒸发点，因此与实验研究中报道的稳定熔化轨迹一致。为了进一步证实所提出的有限元传热模型的有效性，将熔池与基体接触宽度和粉末消耗带宽度的模拟结果与实验结果和模拟结果进行了比较。文学。最后，进行模拟以预测 SLM 过程中单扫描熔体轨迹的稳定性条件。