单道多层LMD成形过程沉积尺寸波动分析与预测

Analysis and prediction of deposit size fluctuation in single-track multilayer LMD forming process

激光熔化沉积技术(LMD)可快速制造高性能的复杂结构零件,但是在零件成形过程中存在沉积尺寸不稳定的工艺现象。面向激光熔化单道多层沉积过程,开展实验研究分析了关键工艺参数对沉积尺寸的影响规律。结果表明:同一沉积层内的沉积尺寸整体趋于稳定;由于热累积效应等因素,在接近基板的区域内的不同层间的沉积尺寸整体波动较大,而在堆积到一定层数后尺寸波动减小;进一步分析了不同沉积区域内激光功率和扫描速度与沉积宽度及高度之间的关系,并建立了基于工艺参数的多层沉积尺寸预测模型,模型预测误差在5%以内。该研究为后续激光熔化沉积过程的尺寸稳定控制及工艺参数优化提供了依据。

Laser melting deposition technology can quickly manufacture high-performance parts with complex structures,but there is a phenomenon of unstable deposition size during the part forming process.An experiment was conducted to analyze the influence of key process parameters on the deposition size for the laser melting single-track multilayer deposition process.The results indicate that the deposition size in the same deposition layer tends to stabilize as a whole.Due to factors such as the thermal accumulation effect,the deposition size between different layers in the area close to the substrate fluctuates greatly,while the size fluctuation decreases after a certain number of layers are accumulated.The relationship between the laser power and scanning speed and the deposition width and height in the different deposition areas is further analyzed,and a multi-layer deposition size prediction model based on process parameters is established,and the prediction error of the model is within 5%.The study provides a foundation for the dimensional stability control and process parameter optimization of the subsequent laser melting deposition process.