Design And Experimental Study Of Polishing Device With Negative Compressibility

In the middle and late 20 th century,with the rapid development of computer technology,it began to be widely used in the field of ultra-precision machining.As a result,a variety of modern polishing technologies emerged,which greatly improved the processing accuracy and processing efficiency of optical surfaces.Ho wever,there are still some shortcomings of the modern polishing technologies.In the polishing process of the ultra-smooth surfaces,high processing efficiency and high processing accuracy are often difficult to achieve simultaneously.It is also difficult to achieve adaptive polishing for different areas of the surface of the workpiece.In view of the shortcomings of the modern polishing technologies,this paper designs a new polishing device with negative compressibility on the basis of the polishing principle of negative compressibility.Then various experimental studies ha ve been made of the polishing device.The main contents and conclusions of this article are as follows:(1)Based on the polishing principle of negative compressibility,a new polishing device with bigger negative compressibility is designed.This polishing device uses octahedron wine-rack structure as the core unit.The negative compressibility of the octahedron wine-rack structure is analyzed.Appropriate parameters are selected and used to manufacture a 4×4×4 three-dimensional unit with negative compressibility.This polishing device is simulated and optimized with ANSYS finite element software,and a set of optimization parameters is finally obtained.The negative compressibility of the polishing device is tested using a laser displacement sensor.The results show that the negative compressibility of the polishing device is big enough.(2)Based on the Preston hypothesis,the models of material removal function and edge removal function of CCOS technology are established.Then simulation analysis and experimental verification are carried.The experimental results prove the correctness of these two models.The effect of the negative compressibility of the polishing device on the removal function is analyzed using the comparative experimental method.The experimental results show that the negative compressibility of the polishing device does not affect the overall shape of the removal function,but it reduces the material removal efficiency.The calculation of the coefficient k in the Preston hypothesis is performed for several experiments,and the results show that the coefficient k will change with the polishing parameters and other polishing conditions.(3)The effect of each process parameter on the surface roughness and material removal efficiency of workpiece is analyzed using orthogonal experimental methods.The degree of influence of polishing agent particle size,polishing time,polishing force,and polishing tool rotation speed on the surface roughness is successively weakened.The degree of influence of polishing agent particle size,polishing force,polishing tool rotation speed,and polishing agent concentration on the material removal efficiency is successively weakened.Considering the effect of various process parameters on the surface roughness and material removal efficiency of the workpiece,the best combination of process parameters is obtained.(4)Polishing experiments are performed on the negative compressibility of the polishing device.Based on the combination of process parameters that favors the surface roughness of the workpiece,polishing experiments are performed with and without the use of the polishing device.The experimental results show that the negative compressibility of the polishing device plays a role in improving the surface quality of the workpiece.The effect of the polishing time on the negative-compressive polishing is analyzed using the comparative experimental method.The experimental results show that the effect of negative compressibility on polishing gradually decreases with the increase of time.