Research On Key Technologies Of Vibration-Assisted Magnetorheological Polishing

With the rapid development of optics,communications,semiconductors,aerospace technology and the continuous emergence of high-performance,high-precision,highly integrated optoelectronic systems,more stringent requirements are placed on the precision machining of hard and brittle materials such as optical glass,silicon carbide,tungsten carbide,sapphire,zirconia,etc.Magnetorheological polishing technology can improve the surface quality of parts,maintain and improve the surface accuracy of the machined surface.The surface of the parts processed by magnetorheology not only has lower surface roughness,but also has the advantages of wear resistance,corrosion resistance and fatigue resistance,and at the same time can obtain higher microscopic shape accuracy.In order to further improve the processing efficiency and improve the quality of the machined surface,the existing magnetorheological polishing should be combined with other processes to expand its application range.Vibration-assisted magnetorheological polishing is a polishing method that combines vibration polishing and magnetorheological polishing.In the process of magnetorheological polishing,vibration is applied to the workpiece or magnetic pole to achieve the purpose of improving polishing efficiency and improving surface quality.Therefore,it is of great significance to the ultra-precision machining industry to explore the vibration-assisted magnetorheological polishing technology suitable for processing hard and brittle materials.Aiming at the problems of surface / subsurface damage in the processing of hard and brittle materials,this paper proposes a non-resonant rotary vibration assisted magnetorheological polishing method.First,a rotary vibration assisted magnetorheological polishing device was developed,and then the key technologies of rotary vibration assisted magnetorheological polishing were studied theoretically and experimentally.Specific research contents include:(1)Combining the processing characteristics of magnetorheological polishing and the characteristics of piezoelectrically actuated rotary flexible vibration assisted processing devices,a new type of vibration-assisted magnetorheological polishing system is developed.Firstly,the flexibility modeling and static analysis of the designed rotary vibration device are carried out based on the matrix method.Then,the static and dynamic characteristics of the designed rotary vibration device are researched by the finite element analysis method,and verified the accuracy of the theoretical analysis model of the static parameters of the designed rotary vibration device.Through the open and closed loop device performance test experiments,it is determined that the designed rotary vibration device can meet the technical requirements of vibration-assisted magnetorheological polishing.(2)Using FEM / SPH simulation technology,a three-dimensional model of single abrasive grain simulation of silicon carbide polishing was established to analyze the mechanism of tangential force change during vibration-assisted magnetorheological polishing,and the influence of different processing parameters on material removal rate and surface roughness.Through the analysis of numerical simulation data,the variation law of the processed surface under the influence of vibration and non-vibration process parameters is obtained.(3)Vibration-assisted magnetorheological polishing experiment was carried out,and then the polished silicon carbide workpiece was tested to obtain the change law of surface morphology and tangential force under different vibration parameters.The effectiveness of the rotational vibration assisted magnetorheological processing method and device was verified.