Modeling of Temperature Field Evolution During Multilayered Direct Laser Metal Deposition
Modeling of Temperature Field Evolution During Multilayered Direct Laser Metal Deposition
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DOI：
10.1007/s11666-017-0554-5
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发表时间：
2017-04
影响因子：
3.1
通讯作者：
Dongyun Zhang;Zheli Feng;Chengjie Wang;Z. Liu;Dongdong Dong;Yan Zhou;R. Wu
中科院分区：
文献类型：
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作者：
Dongyun Zhang;Zheli Feng;Chengjie Wang;Z. Liu;Dongdong Dong;Yan Zhou;R. Wu
深入研究垂直薄壁制造过程中直接激光金属沉积(简称LMD)过程中的温度场变化规律具有重要意义。这有助于控制温度梯度，甚至调整组织的形成和残余应力的积累。本文建立了一个完整的三维暂态温度场演化模型。制造材料为DS高温合金Rene80。首先模拟了粉末流动过程中激光与粉末的相互作用，分析了激光与粉末相互作用对熔池温度场的可能影响。在此基础上，考虑LMD过程中的相变、喷粉和液体流动等输运现象，对LMD过程中的温度场演化进行了三维数值模拟。应用的沉积参数是从实验研究中得出的，并优化了垂直壁的制造。模拟结果解释了竖直薄壁内部热输入与散热平衡的原因。在没有任何温度控制单元的情况下，重建了建筑过程早期的不稳定性，并展示了激光功率、沉积速度和激光束沉积图案等参数的影响。温度演变的模拟结果与实验研究相吻合。
It is of great importance to thoroughly explore the evolving temperature fields of direct laser metal deposition (abbreviated as LMD) in vertical thin wall manufacturing. It is helpful to control the temperature gradient, and even to adjust to forming microstructures and accumulation of residual stress. In this paper, a comprehensive three-dimensional transient model is developed for evolving temperature fields. The manufactured material is DS superalloy Rene80. The laser-powder interaction during the powder flowing process is simulated first, and its possible effect on the temperature field of the melting pool is analyzed. Then a 3D numerical simulation for the evolving temperature field is carried out based on considering transport phenomena during LMD such as the change in phase, powder injection and liquid flow. The applied deposition parameters are derived from experimental investigation with optimized vertical wall manufacturing. The simulated results explain why a balance between heat input and dissipation could form inside the vertical thin wall. These reconstruct the instability at an early phase of the building process without any temperature control unit and exhibit the influence of parameters such as laser power, deposition velocity and laser beam deposition pattern. The simulation results of temperature evolution are consistent with experimental investigation.