Study On Effects Of Magneic Field And Magnetorheological Fluids On Magnetorheological Polishing

Magnetorheological polishing(MRP)is an important method for processing high-precision optical components.It is suitable for various types of workpieces and does not produce sub-surface damage.Moreover,it not only has the advantages of stable removal function,high shaping accuracy,no wear of the polishing head,high material removal efficiency,but also does not introduce subsurface damage.This dissertation researches some factors which impact polishing on MRP process parameter,and the mainly studies are:The polishing mechanisms of MRP were studied first.The material removal model was established based on the polishing removal theory to analyze the force and removal process during polishing.The ANSYS Workbench software was used to simulate the process parameters such as the immersion depth,the size of the ball diameter and the speed of the polishing particles,and the removal of the material surface,the force acting on the abrasive particles and the stress of the support plane were obtained.The simulation results show that with the decrease of the immersion depth of the abrasive particles,the removal amount of the protrusion on the surface of the material is also reduced,the force of the abrasive particles is almost unchanged,and the support force of the plane where the protrusion is located is increased;With the increase of particle diameter,the removal of the material's surface protrusion increases,and the force and support force of the abrasive particles increase.With the increase of the abrasive particle velocity,the removal of the material surface protrusion increases.The force and support force of the abrasive particles also increase.The gradient magnetic field of the excitation device is studied based on the theoretical calculation and simulation analysis.The gradient magnetic field generated by the excitation device was calculated based on the static magnetic field theory.The magnetic field was simulated and analyzed using ANSYS Workbench software.The magnetic field distribution law under permanent magnet excitation mode and the influence of the distribution law on the flexible polishing tool was studied.The magnetic pole thickness,air gap width,and yoke width affect the magnetic flux density and polishing pattern of the magnetorheological fluid at different sizes,and its size is optimized.The magnetic flux density generated above the optimized excitation device is enhanced,the magnetic field width is increased,the formed magneto-rheological polishing tool becomes wider,and the polishing area increases.The polishing characteristics of MRP were tested with the used of built experiment platform.The whole MRP experiment system was set up according to the positive MRP device.The polishing effect of K9 glass was tested under different polishing wheel speed,immersion depth and magnetic field intensity.The micro observation of the workpiece after polishing was observed with the three-dimensional microscope of super depth of field,and the removal depth was measured with three coordinate measuring instrument,and the removal was calculated.The results show that the removal of the material increases with the increase of the immersion depth,the speed of the polishing wheel and the intensity of the magnetic field,and the test results are in good agreement with the simulation results.