结合激光刻蚀手段与数控加工技术, 提出了一种基于数控激光铣削的工程塑料表面金属覆层定域精细去除方法。考虑不同位置的零件对加工质量的要求不同, 通过激光烧蚀实验结果得到了保证图形边缘质量的精密切边加工工艺并确定了相应的工艺参数。开发了基于实际进给速度自适应调整激光能量的覆层金属定厚度高效去除技术, 完成了图形内部余量的去除, 解决了机床实际进给速度受动态性能限制无法达到预设值而导致的目标材料过烧蚀问题。最后, 以典型零件复合式三维信号发送/接收器为例, 通过对工件图形分区域变参数加工验证了所提出的方法的可行性。实验结果表明: 采用基于数控激光铣削的金属覆层定域精细去除技术能够完成典型样件的精密加工, 加工的三维金属图形衔接精准, 边缘光顺整齐, 热影响区范围小, 能够满足该类零件高质高效的制造要求。

In combination of laser etching and numerical control (NC), a localized and precision removal technology for metal coating on engineering plastics was proposed based on numerical control (NC) laser milling. As different positions of the parts require different qualities, a precise processing technology was presented through study and analysis of laser ablation experiments to guarantee the quality of figure edge and corresponding technological parameters were determined. Then, the removal technology for the metal coating with a constant depth was developed by adaptive controlling the laser fluence on the basis of the practical feed speed, by which the allowance within the pattern was removed and the over-ablation problem of the processed materials caused by that the machine feed speed can not reach to a preset value was solved. Finally, a compound three-dimension signal transmission/receiver was taken as an example, the feasibility of the proposed method was verified by processing the part pattern regionally. Processing results show that the compound three-dimension signal transmission/receiver has been processed precisely with the localized and precision removal technology based on numerical control (NC) laser milling. The join of the plane part and the conical part is accurate, the neat micro-strip edge is smooth and almost no heat affected zone. The results meet the requirements of manufacturing the part with high quality and high efficiency.