Investigation On Laser Micro-milling Combined Machining Of S-shaped Deep And Narrow Microgrooves

Deep and narrow microgrooves have extensive applications in the defence,commercial and other fields.Its dimensional accuracy and surface integrity play a crucial role in the overall performance of micro devices.Recently,micro-milling technology has been frequently used to fabricate deep and narrow microgrooves owing to high-precision,flexibility and efficiency.However,short tool life and poor machining surface integrity are the key issues still reported in published studies.In order to address the above-mentioned issues,a novel laser micro-milling combined machining is developed to generate S-shaped deep and narrow microgrooves.In addition,the potential advantages of this new laser micromilling combined machining are analyzed by carryout a holistic analysis based on the design of experiments.The main contents of this research work are as follows:(1)Using COMSOL Multiphysics software,the thermal effect of laser-ablated oxygen-free copper was simulated to establish a heat transfer model between laser and workpiece material.The physical properties of the material were presented as a function of temperature change to set the parameters in the simulation model.The phase transition process of the material is arranged,and the material removal phenomenon generated by the phase change is simulated by using the moving grid method.The influence of laser process parameters on the ablation depth and temperature field distribution is obtained.(2)The numerical simulation results underscored the effects of different laser scanning strategies,laser intensity,scanning speed,and the number of scans on the formation of deep and narrow microgrooves of oxygen-free copper were studied.The laser processing parameters were investigated on the heat-affected layer of oxygen-free copper materials characteristics such as hardness,cutting depth and the influence of surface microstructure.Based on the response surface methodology,a quantitative relationship between responses and variables was established,and multi-objective optimization was performed.(3)After laser machining,the machinability of the workpiece material under micro milling is investigated to analyze the variations of the milling force,the surface quality,and tool wear by one-way full-groove milling and one-way compound milling of deep and narrow microgrooves.Finally,a 30-cycle S-shaped deep and narrow microgrooves with a characteristic width of 0.2 mm and an aspect ratio of 2.5 was successfully prepared.