Research On The Wear Mechanism And Suppression Methods Of Magnetorheological Polishing Wheels

During the magnetorheological polishing process,the magnetorheological polishing wheel acts as a carrier tool for the polishing ribbon and plays a vital role in the polishing process and circulation system.When used for a long time,the surface of the polishing wheel will have a certain degree of wear,forming grooves of different depths and uneven distribution,there will also be different extents oxidation of polishing fluid,which have certain influence on polishing quality,polishing liquid circulation system and polishing tool life.However,the research on the wear of the magnetorheological polishing wheel is lacking and not deep enough.In order to solve the problem of wear of magnetorheological polishing wheel,this paper studies the wear of magnetorheological polishing wheel by four aspects:wear identification and detection,wear oxidation,wear mechanism and wear suppression.The main work is divided into the following aspects:(1)Combined with the surface wear characteristics of the magnetorheological polishing wheel,the wear failure mode and characterization method of the polishing wheel are clarified.A method for detecting the wear surface appearance of the polishing wheel based on the principle of dispersion and confocality is proposed.The wear profile detection platform of the polishing wheel is built to verify the technical feasibility of the wear of the magnetorheological polishing wheel without disassembly.(2)Based on the XPS spectrometer monitoring analysis,it was confirmed that the main component of the surface oxide of the magnetorheological polishing wheel is iron oxide.By analyzing the possible ways of generating oxides during the wear of the polishing wheel,it was found that the iron oxide was mainly produced by the high-speed friction process between the iron powder and the polishing wheel in the magnetic seal at the recycler.Combined with experiments,the formation mechanism of oxides was clarified,and the adhesion of oxides on the surface of the polishing wheel was mastered.Preliminary research showed that the main factors affecting the adhesion of iron oxide on the surface of the polishing wheel were the scale of the polishing powder and the surface morphology of the coating.(3)According to the wear problem of the magnetorheological polishing wheel,the cause of the wear is clarified.The wear mechanism of the semi-fixed abrasive grain of the polishing wheel is analyzed,and the main factors of the wear of the polishing wheel are clarified.By studying the influence of the regenerator gap,the rotation speed of the polishing wheel,the scale and concentration of the polishing particles on the wear rate of the polishing wheel,the surface morphology and surface roughness of the polishing wheel after wear were analyzed by SEM and profiler.The experiment results indicate that the semi-fixd abrasive wear between the magnetic seal forming by recycling device and polishing wheel is the main reason of magnetorheological polishing wheel wear,and the wear characteristics shows that both two-body wear and three-body wear exist in the wear process.The root causes of changing of wear rate are the magnetic field intensity and the distortion degree of magnetic chain.The wear rate decreases with the increase of the gap length between the polishing wheel and recycling device,and first increases then decreases as the polishing wheel rotation speed,concentration and size of the polishing abrasive rise up,the variation tendency of wear rate changing of these factors concides with theoretical analysis.(4)Based on the existing magnetorheological polishing wheel wear suppression method,the method of suppressing the wear of the polishing wheel is studied from the two aspects of wear-resistant coating and recovery principle.By comparing the wear resistance of the existing coating with the superhard ceramic coating,it is found that the coating wear resistance is not positively correlated with the layer hardness.According to the wear mechanism of the polishing wheel,the polishing wheel wear suppression method for the isolation polishing powder is proposed,and the feasibility is verified by experiments.