论文标题
定向能量沉积的二维热有限元模型：匹配熔体池温度曲线与高温计测量
Two-dimensional thermal finite element model of directed energy deposition: matching melt pool temperature profile with pyrometer measurement
论文作者
论文摘要
使用基于Python的Fenics Framework开发了定向能量沉积（DED）过程的开源二维（2D）热有限元（Fe）模型。该模型根据零件的几何形状在激光聚焦点之前逐渐沉积材料。激光热能由高斯分布的热源提供，而相变为固体液体温度范围内的热容量增加。数值模型的实验验证是通过与盒形Ti-6Al-4V部分具有大量几何空隙的材料构建过程中双波长高温计进行的熔体池温度测量来执行的。检查了大几何空隙对熔体池形状和最大熔体池温度的影响。数值和实验数据均表明在大空隙上方沉积过程中熔体池的尺寸和温度增加。使用开发的数值模型获得的熔体池温度曲线的后缘与高温计测量值匹配。
An open source two-dimensional (2D) thermal finite element (FE) model of the Directed Energy Deposition (DED) process is developed using the Python-based FEniCS framework. The model incrementally deposits material ahead of the laser focus point according to the geometry of the part. The laser heat energy is supplied by a Gaussian-distributed heat source while the phase change is represented by increased heat capacity around the solidus-liquidus temperature range. Experimental validation of the numerical model is performed by matching with the melt pool temperature measurements taken by a dual wavelength pyrometer during the build process of a box-shaped Ti--6Al--4V part with large geometrical voids. Effects of large geometrical voids on the melt pool shape and maximum melt pool temperature are examined. Both the numerical and experimental data show an increase in the melt pool size and temperature during deposition above large voids. The trailing edge of the melt pool's temperature profile obtained using the developed numerical model closely matches pyrometer measurements.
