A Lagrangian meshfree mesoscale simulation of powder bed fusion additive manufacturing of metals
A Lagrangian meshfree mesoscale simulation of powder bed fusion additive manufacturing of metals
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DOI：
10.1002/nme.6546
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发表时间：
2020-09
影响因子：
2.9
通讯作者：
Zongyue Fan;Hao Wang;Zhida Huang;Huming Liao;Jiang Fan;Jian Lu;Chongying Liu;Bo Li
中科院分区：
文献类型：
--
作者：
Zongyue Fan;Hao Wang;Zhida Huang;Huming Liao;Jiang Fan;Jian Lu;Chongying Liu;Bo Li
我们提出了一个粉末规模的计算框架，预测金属的微观结构演变的粉末床熔融增材制造（PBF AM）过程的基础上热最佳传输无网格（HOTM）方法。通过整合来自实验的统计信息（包括颗粒尺寸和形状以及粉末堆积密度），将粉末床建模为离散且可变形的三维体。在拉格朗日框架中的牵引力被开发来模拟反冲压力和表面张力。激光束以热通量的形式动态地作用于颗粒和基体表面，用户可以指定激光束的尺寸、功率、扫描速度和路径。线性动量和能量守恒方程在拉格朗日配置中建立，并通过HOTM方法以整体方式同时求解，以预测粉末床中的变形、温度、接触机制和流体-结构相互作用。数值计算结果与单轨道试验结果进行了对比验证。各种粉末床配置，激光功率和速度进行了研究，以了解动态接触和非弹性材料行为的变形，传热和相变的粉末床的影响。通过所提出的计算方案预测了3D打印金属微观结构中缺陷的形成，包括孔隙，部分和未熔化的颗粒。
We present a powder‐scale computational framework to predict the microstructure evolution of metals in powder bed fusion additive manufacturing (PBF AM) processes based on the hot optimal transportation meshfree (HOTM) method. The powder bed is modeled as discrete and deformable three‐dimensional bodies by integrating statistic information from experiments, including particle size and shape, and powder packing density. Tractions in Lagrangian framework are developed to model the recoil pressure and surface tension. The laser beam is applied to surfaces of particles and substrate dynamically as a heat flux with user‐specified beam size, power, scanning speed, and path. The linear momentum and energy conservation equations are formulated in the Lagrangian configuration and solved simultaneously in a monolithic way by the HOTM method to predict the deformation, temperature, contact mechanisms, and fluid‐structure interactions in the powder bed. The numerical results are validated against single track experiments. Various powder bed configurations, laser powers, and speed are investigated to understand the influence of dynamic contact and inelastic material behavior on the deformation, heat transfer, and phase transition of the powder bed. The formation of defects in the microstructure of 3D printed metals, including pores, partially, and unmelted particles, is predicted by the proposed computational scheme.