【摘要】 采用离散元（DEM）与流体体积（VOF）相结合的方法，以IN718粉末的激光选区熔化（SLM）过程为研究对象，通过数值模拟和试验验证，研究了激光功率对熔池尺寸的影响，以及熔池演化和熔道形貌的形成机理。结果表明，随着激光功率增大，熔池尺寸逐渐增大，熔池连续性和尺寸均匀性增强，合适的工艺参数（P=200 W,v=1.5 m/s）会获得最佳熔道形貌；由温度梯度引起的表面张力梯度与蒸气反冲压力共同驱动了熔池的演化和熔道形貌的形成；优化层间旋转角（θ=67°）能够降低熔道两端孔缺陷出现的概率。更多还原

【Abstract】 Utilizing a combined discrete element method(DEM) and volume of fluid(VOF) approach, effects of laser power on the melt pool size and formation mechanisms of evolution and morphology of IN718 during selective laser melting(SLM) were investigated through numerical simulation and experimental validation. The results reveal that with an increase in laser power, the melt pool size is gradually enlarged and the continuity and size uniformity of the melt pool is improved. Optimal melt track morphology is achieved at specific process parameters(P=200 W, v=1.5m/s). The surface tension gradient induced by the temperature gradient, coupled with the vapor recoil pressure, jointly drive the evolution of the melt pool and the formation of the melt track. Optimizing the interlayer rotation angle(θ=67°) can reduce the probability of pore defects at the ends of the melt tracks.更多还原