| In view of the uneven grinding force in the grinding process of the flat grinding wheel of the ceramic mobile phone surface cover,the uneven grinding surface roughness,serious grinding tool marks,and large residual stress lead to the loss of ceramic material,and the grinding wheel cannot completely process the convex surface of the side wall.Therefore,it has caused problems such as the need for multiple processing procedures,low processing efficiency,high processing cost and low yield.This article applies ultrasonic processing technology to ceramic surface grinding processing,and uses the high-frequency vibration brought by ultrasonic to drive abrasive particles to scratch,Extrusion,cutting,collision to achieve the purpose of high-efficiency removal of ceramic materials.In this paper,the mobile phone ceramic surface cover is used as the processing object,and the ultrasonic vibrator specially used for ceramic surface grinding is designed.The grinding tool head is innovatively designed under the ordinary ultrasonic surface grinding processing method,and the vibrator is simulated and impedance by Comsol.The analyzer and oscilloscope are used for performance testing;an ultrasonic planar ceramic grinding platform is built,and the influence of processing distance,abrasive particle size,processing feed rate,excitation voltage,abrasive particle size,etc.on the ceramic surface roughness is explored through experiments,and the process is optimized parameter.The main work and results are as follows:(1)By deriving the frequency equation formula of the variable cross-section thin rod,and using the frequency equation to calculate the length of the transducer and the horn according to the requirements of ultrasonic frequency and wavelength.Analyze and design a tool head suitable for surface grinding according to the internal shape of the mobile phone cover,establish a fluid model,conduct a coupled analysis of the flow field and sound field of the abrasive suspension under the excitation of the tool head with a microstructure,and verify the tool The efficiency of the head and the completion of the assembly of the vibrator and the adjustment of the horizontal position of the ultrasonic vibrator;(2)Using Comsol to perform modal analysis on the ultrasonic vibrator to detect the rationality and error of the design of the transducer and the horn,to analyze whether the shape will have a serious effect on the vibrator,to modify the position and thickness of the flange,and simulate the designed ultrasonic The resonant frequency and mode shape of the vibrator are analyzed for consistency with the designed vibrator.Using harmonic response analysis.Under the condition of electrostatic excitation,the piezoelectric performance of piezoelectric ceramic sheet is converted from electrical energy and mechanical vibration energy,and the difference between the conversion into ultrasonic vibration and the expected vibration trend is analyzed;impedance analysis is used to test the impedance performance of the vibrator Match the capacitance and inductance of the ultrasonic power supply to the vibrator;use the oscilloscope to test the amplitude of the vibrator’s input voltage and current,use the laser displacement sensor to test the longitudinal displacement of the vibrator,and analyze the effect of the ultrasonic excitation voltage on the vibrator,and obtain the voltage pair The amplitude of the ultrasonic vibrator affects the graph,and the vibration stability of the vibrator is judged to provide a guarantee for the ultrasonic surface grinding test.(3)Using Mach 3 to set the processing operating conditions and methods,and finally debug the vibrator and the three-dimensional processing motion platform;perform the ultrasonic flat ceramic grinding Cutting process test: Designed a single factor test on feed speed,processing distance,and abrasive particle size,and compared and analyzed the difference effects of each influencing factor,and found that the best processing distance range is 20-40 um,The optimal feed speed range is 0.3-1.5mm/min,and the most qualified abrasive particle size is 15meshes;(4)Orthogonal experiments on ultrasonic flat ceramic grinding are designed,and the roughness and variance analysis are carried out.The effect of various factors on ultrasonic flat ceramic grinding is obtained.The machining distance and excitation voltage have a significant impact on the grinding force,and the machining speed has a significant impact on the surface deviation.The optimal test parameter is obtained as the best test parameter in the abrasive The particle size is 15 meshes,the processing pitch is 20μm,the excitation voltage is 90 V,and the processing speed is 0.5mm/min. |
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