Wang Xiang, Zhang Lin-Jie, Ning Jie, Na Suck-Joo
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, China.
3D Print Addit Manuf. 2023 Aug 1;10(4):661-673. doi: 10.1089/3dp.2021.0159. Epub 2023 Aug 9.
A 3D numerical model of heat transfer and fluid flow of molten pool in the process of laser wire deposition was presented by computational fluid dynamics technique. The simulation results of the deposition morphology were also compared with the experimental results under the condition of liquid bridge transfer mode. Moreover, they showed a good agreement. Considering the effect of recoil pressure, the morphology of the deposit metal obtained by the simulation was similar to the experiment result. Molten metal at the wire tip was peeled off and flowed into the molten pool, and then spread to both sides of the deposition layer under the recoil pressure. In addition, the results of simulation and high-speed charge-coupled device presented that a wedge transition zone, with a length of ∼6 mm, was formed behind the keyhole in the liquid bridge transfer process, where the height of deposited metal decreased gradually. After solidification, metal in the transition zone retained the original melt morphology, resulting in a decrease in the height of the tail of the deposition layer.
采用计算流体力学技术建立了激光填丝熔敷过程中熔池传热与流体流动的三维数值模型。在液桥过渡模式下，将熔敷形貌的模拟结果与实验结果进行了对比，二者吻合良好。考虑反冲压力的影响，模拟得到的熔敷金属形貌与实验结果相似。焊丝端部的熔融金属被剥离并流入熔池，然后在反冲压力作用下向熔敷层两侧铺展。此外，模拟结果和高速电荷耦合器件结果表明，在液桥过渡过程中，小孔后方形成了一个长度约为6 mm的楔形过渡区，该区域内熔敷金属高度逐渐降低。凝固后，过渡区内的金属保留了原始熔体形貌，导致熔敷层尾部高度降低。
