Study On The Surface Quality Of Microcrystalline Mica Ceramic Ultrasonic Grinding In Small Deep Holes

With the rapid development of science and technology,ceramic materials have always been a difficult problem in machining because of their hard and brittle properties.As for small diameter deep holes,low production efficiency and poor surface quality of processed holes limit their development in national defense and aerospace.Ultrasonic Vibration Grinding technology(Ultrasonic Vibration Grinding,UVG)combines traditional Grinding machining with the new method of Ultrasonic Vibration machining,with technology advantage of small cutting force,cutting temperature,suitable for materials which are difficult in machining like ceramic etc.It is of great significance to sutdy on the removal mechanism and surface quality of microcrystalline mica ceramic ultrasonic grinding in small deeo holes which promotes the development of the material in the fields of aerospace and national defense and the application of deep hole machining of ceramic materials.The unique mechanical,physical and mechanical properties of microcrystalline mica ceramics are the key factors influencing their processing performance.This study discusses the removal mechanisms of microcrystalline mica ceramic,the influence of dynamic and static load on the depth of the critical load of plastic brittleness removal conversion and,the influence of cutting parameters on the characterization of force,the influence of surface topography;The mathematical model and multivariate regression model of grinding force are established,and the influence law and degree of technological parameters on grinding force are analyzed.Finally,the surface roundness error of deep hole is evaluated,the roughness information of machining surface is extracted,and the effect of grinding parameters on machining surface quality is analyzed.In this paper,the experimental method of wedge scratch is used to compare the removal of materials and the changing law of grinding force in the actual machining process with or without ultrasonic vibration.The grinding model of microcrystalline mica ceramics material is established by using the finite element software ls-dyna.And the effect of ultrasonic vibration on the processing quality is simulated and analyzed.The results of scratch experiment and simulation show that ultrasonic vibration assisted machining is beneficial to improve machining efficiency and surface quality.Secondly,the mathematical model of grinding force of ultrasonic grinding deep hole is established according to the processing characteristics of ultrasonic vibration grinding particles,the simultaneous theory and the actual material removal rate equation.The second step is to design the single factor and orthogonal test and reduce the noise of grinding force data by wavelet transform with the maximum grinding force taken as the research object.Studies have shown that the grinding force can be greatly reduced by ultrasonic vibration and it decreases with increasing the ultrasonic power and spindle speed,increases as the feed speed.The influence degree from big to small in order is the spindle speed,ultrasonic power,feed speed.Finally,the surface quality of the deep hole is studied.Filtering and contour extraction of deep hole entrance surface is carried out based on the digital image processing technology.This study evaluates the roundness error using the minimum zone method.The influence law of process parameters on the roundness error is analyzed by single factor and orthogonal test analysis.Based on the macro profile analysis of the hole surface,the factors affecting the surface roughness of the deep hole are analyzed.The results show that the increase in spindle rotation speed and the ultrasonic power,decrease in the feed speed method can reduce the surface roughness of deep holes.Ultrasonic vibration can dramatically improve the processing quality of ceramic deep holes.