Modeling And Simulation Of Surface Microstructures In Rotary Ultrasonic Milling And Its Performance Researc

As the design and fabrication of functional surface microstructures has become the current research focus,the fabricating methods of isotropic microstructures with high processing efficiency,low machining cost,and large quantity are the key development trend.In this study,rotary ultrasonic milling(RUM)technology was proposed to rapidly realize surface microstructures.The surface microstructure simulation prediction model was established to analyze the generation of the microstructure in RUM,and the wettability and anti-reflection characteristics were experimentally explored.The main contents and conclusions are as follows:(1)A theoretical simulation model of the surface microstructure in RUM was build and the simulation analysis was implemented with it.According to the kinematic characteristics of RUM,a surface microstructure simulation prediction model consist of different simplified model of tool tip geometry was established,and the characterization parameters for microstructure were presented.The tool tip cutting trajectory analysis was carried out,which state under different ultrasonic frequencies,ultrasonic amplitudes and spindle speeds was explored,and it was found that different tool tip trajectory was consistent under the same f/n.The microstructure simulation experiment was carried out to analyze the influence of the tool tip geometry,processing parameters,ultrasonic parameters and machining interference on the generation of microstructure,and the phenomenon of intermittent and continuous milling and its conditions were put forward.The results show that the tool tip corner radius and the rake angle have a great impact on the microstructure unit,and the spindle speed and feed speed comprehensively affect the feed per tooth,thereby changing the length and spacing of the microstructure along the feed direction,the ultrasonic frequency and the spindle speed comprehensively affects the circumferential spacing,width and arrangement inclination of the micro-pits.(2)The verification experiment and improvement of the surface microstructure simulation model in rotary ultrasonic milling was carried out.Firstly,the surface microstructure simulation model of RUM was verified by milling experiments,and the surface microstructure simulation model was improved in consideration of tool runout.Then a simulation experiment was carried out to analyze the influence of the process parameters on the microstructure geometry and arrangement,and the functional relationship between the process parameters and the feed direction spacing as well as arrangement inclination angle of the microstructure was updated at the same time.Finally,the improved simulation model was verified by experiments.The results show that the shape and size of the microstructure resemble,the error of spacing distance does not exceed 3%,and the error of surface roughness is within 13% between the predicted surface and the milled surface.(3)Research on simulation design of microstructure in RUM for wettability and antireflection properties was implemented.On the one hand,the surface microstructure of RUM for wettability property was designed by simulation.The surface microstructure with raised contact angle was designed by reducing the spindle speed,increasing the ultrasonic amplitude and feed speed to improve the depth and sidewall inclination of the microstructure.On the other hand,the simulation design of surface microstructure of RUM was carried out for the anti-reflection characteristics.It is proposed that the microstructure is deepened by increasing the ultrasonic amplitude,and the density of microstructure is increased by reducing the spindle speed and feed speed.Then,the surface microstructure with low optical reflectivity is obtained by simulation design.