Prediction of meltpool features in Laser-Based Powder Bed Fusion (LB-PBF) is a complex non-linear multiple phase dynamic problem. In this investigation, numerical simulations and analytical models are offered to predict meltpool temperature and to provide a methodology to estimate melt track quality. By determining the meltpool temperature, different rheological phenomena including recoil pressure can be controlled. Recoil pressure is known to drive the keyhole and conduction modes in LB-PBF which is an important factor to qualify the melt track. A numerical simulation was carried out using Discrete Element Method (DEM) with a range of process parameters and absorptivity ratios; allowing observation of the variation of meltpool temperature and free surface morphology, as calculated by the volume-of-fluid (VOF) method. A spatially thermophysical-based analytical model is developed to estimate meltpool temperature, based on LB-PBF process parameters and thermophysical properties of the material. These results are compared with experimentally observed meltpool depth for IN718 specimens and found to have a good accuracy. The numerical and analytic results show good agreement in the conduction mode to estimate the meltpool temperature and related phenomena such as recoil pressure to control the melt track and layering quality. The analytical model does not accurately predict the keyhole mode which may be explained by evaporation of chemical elements in the examined material.

基于激光的粉末床融合 (LB-PBF) 中熔池特征的预测是一个复杂的非线性多相动态问题。在这项研究中，提供了数值模拟和分析模型来预测熔池温度并提供一种估计熔体轨迹质量的方法。通过确定熔池温度，可以控制包括反冲压力在内的不同流变现象。众所周知，反冲压力会驱动 LB-PBF 中的锁孔和传导模式，这是限定熔体轨迹的重要因素。使用离散元法 (DEM) 进行数值模拟，具有一系列工艺参数和吸收率；允许观察熔池温度和自由表面形态的变化，如通过流体体积 (VOF) 方法计算的。基于 LB-PBF 工艺参数和材料的热物理特性，开发了一种基于空间热物理的分析模型来估计熔池温度。将这些结果与 IN718 试样的实验观察到的熔池深度进行比较，发现具有良好的准确性。数值和解析结果表明，在传导模式下估计熔池温度和相关现象（如反冲压力）以控制熔体轨迹和分层质量具有良好的一致性。分析模型不能准确预测锁孔模式，这可能是由被检查材料中化学元素的蒸发所解释的。将这些结果与 IN718 试样的实验观察到的熔池深度进行比较，发现具有良好的准确性。数值和解析结果表明，在传导模式下估计熔池温度和相关现象（如反冲压力）以控制熔体轨迹和分层质量具有良好的一致性。分析模型不能准确预测锁孔模式，这可能是由被检查材料中化学元素的蒸发所解释的。将这些结果与 IN718 试样的实验观察到的熔池深度进行比较，发现具有良好的准确性。数值和解析结果表明，在传导模式下估计熔池温度和相关现象（如反冲压力）以控制熔体轨迹和分层质量具有良好的一致性。分析模型不能准确预测锁孔模式，这可能是由被检查材料中化学元素的蒸发所解释的。