Abstract

A systematic parametric study was conducted using thermal finite element method simulations in order to calibrate the laser penetration depth and absorptivity as a function of the laser power and scan speed for single tracks of Alloy 718 processed by laser powder bed fusion. A methodology was developed to calibrate both laser penetration depth and absorptivity using an algorithm proposed. Calibrated laser penetration depths and absorptivities captured experimentally observed variations of the melt pool depth and width with the laser power and scan speed, and showed strong correlations with a modified energy density, which is the laser power normalized by a square root of the scan speed (W/(m/s)^1/2). The result indicated that the laser penetration depth and absorptivity heavily influence the determination of the melt pool depth and width, respectively. Variations of calibrated laser penetration depths and absorptivities with the laser power and scan speed reasonably depicted physical phenomena related with how incident laser beam interacts with the melt pool under different input energy densities, and were in quantitative agreement with those calculated from an analytical model and observed from the experiment.

Graphic Abstract

中文翻译：

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基于粉末床熔融熔池有限元分析的激光穿透深度和吸收率标定

摘要

使用热有限元方法模拟进行了系统的参数研究，以校准通过激光粉末床熔合处理的718合金单道激光的穿透深度和吸收率与激光功率和扫描速度的关系。开发了一种使用提出的算法校准激光穿透深度和吸收率的方法。校准的激光穿透深度和吸收率是通过实验观察到的熔池深度和宽度随激光功率和扫描速度的变化而捕获的，并显示出与修正的能量密度的强相关性，能量密度是通过扫描速度的平方根归一化的激光功率（ W /（米/秒）^1/2）。结果表明，激光穿透深度和吸收率分别严重影响熔池深度和宽度的确定。校准后的激光穿透深度和吸收率随激光功率和扫描速度的变化合理地描绘了与入射激光束在不同输入能量密度下如何与熔池相互作用有关的物理现象，并且与从分析模型计算出并观察到的定量结果一致从实验中

图形摘要