激光粉床熔融铝合金熔池热动力学数值模拟

Thermal Dynamic Numerical Simulation of Aluminum Alloy Molten Pool by Laser Powder Bed Fusion

基于有限体积方法建立了激光粉床熔融(LPBF)介观尺度熔化凝固物理模型,考虑了温度函数的热物性参数和材料气化反冲压力模型,研究了激光扫描速度对LPBF成形AlSi10Mg合金非平衡熔池温度场、速度场、残余孔隙与表面品质的影响,揭示了粉末熔化温度场、熔体润湿铺展行为、熔体热毛细流动对表面自由面波动和致密化行为的作用机制,形成的熔池热动力学行为可为调控LPBF成形高致密和高品质表面形貌提供参考。

The mesoscopic-scale melting and solidification physical model of laser powder bed fusion(LPBF)was established based on the finite volume method.Considering the thermophysical parameters of temperature function and the material vaporization recoil pressure model,influence of laser scanning speed on the temperature field,velocity field,residual pores and surface quality of non-equilibrium molten pool in AlSi10 Mg alloy fabricated by LPBF were investigated,and the mechanism that powder melting temperature field,melt wetting and spreading behavior,hot capillary flow of melt act on free surface fluctuation and densification behavior was revealed.The thermodynamic behavior of formed molten pool provides reference for regulating the high-density and high-quality surface morphology by LPBF.