In the Directed Energy Deposition (DED) process, when the mass flow of metal particles is relatively high, the thickness of the layers increases, leading to a more productive process. The higher the mass flow is, the more difficult it becomes to get a stable melt pool. The accumulation of residual heat in the previously consolidated material constitutes a thermal input affecting the balance at the laser-material interaction zone. An accurate control of the temperature of the laser-material interaction zone is critical to maintain the dynamic viscosity of the liquid metal within the narrow margin in which it can be managed in a stable way. The present work introduces a thermal model in which domains with tunable properties are considered to reproduce the growing of the manufactured sample. Concurrently, a virtual closed-loop PID regulator has been implemented in order to calculate suitable values of laser power to compensate the heat accumulated in the material, offering the results from the model as input process parameters to be directly applied in the real process. The levels of laser power proposed by the model have been experimentally applied, leading to a stable process capable of carrying out in reality the desired component.

中文翻译：

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用于可复制 AISI 316L 激光沉积轨道的基于模型的输入能量控制


在定向能量沉积 (DED) 工艺中，当金属颗粒的质量流量相对较高时，层的厚度会增加，从而提高工艺效率。质量流量越高，获得稳定的熔池就越困难。先前固结材料中残余热量的积累构成了影响激光-材料相互作用区域平衡的热输入。精确控制激光-材料相互作用区域的温度对于将液态金属的动态粘度保持在可以稳定管理的狭窄范围内至关重要。目前的工作介绍了一种热模型，其中考虑具有可调属性的域来重现制造样品的生长。同时，还实施了虚拟闭环 PID 调节器，以计算合适的激光功率值来补偿材料中积累的热量，并将模型结果作为输入工艺参数直接应用于实际工艺。该模型提出的激光功率水平已通过实验应用，从而产生了能够在现实中实现所需组件的稳定工艺。