Research On Microstructure Model And Mechanical Properties Of Magnetorheological Polishing Fluids Under The Combined Action Of Magnetic Field And Flow Field

With the continuous development of science and technology,the high-tech industry requires more and more high-precision surface.Because the polishing force is not easy to control and the polishing accuracy is low,traditional surface polishing methods such as mechanical polishing,chemical polishing,and electrochemical polishing are difficult to meet the requirements of various high-precision surfaces.Magnetorheological polishing is a new type of surface polishing technology.It forms a flexible polishing ribbon on the surface of the workpiece based on the rheological properties of the magnetorheological polishing liquid.The polishing force is controlled by changing the magnitude of the magnetic field strength,and then the surface of the workpiece is polished.Magnetorheological polishing fluid is evolved from magnetorheological fluid.The performance of magnetorheological polishing fluid is the key factor affecting magnetorheological polishing technology,so the study of magnetorheological polishing liquid can improve the performance of magnetorheological polishing fluid,and then improve the efficiency and quality of magnetorheological polishing.Based on the micro perspective,this paper explores the microstructure model and mechanical characteristics of the magnetorheological polishing fluid under the combined action of magnetic field and flow field and analyzes the holding mechanism of polishing abrasive particles.The shear yield stress model of magnetorheological polishing fluid under the combined action of magnetic field and flow field is established.The main research work in this paper is as following:(1)Particle dynamics simulation of magnetorheological polishing fluid.Based on the theory of magnetic dipole,the mechanical analysis of the magnetic particles and polishing particles during the evolution of the magnetorheological polishing fluid is performed,and the dynamic equation of the two particles is established.The particle dynamics method is used to simulate the evolution of the magnetorheological polishing fluid,and the effect of the presence of polishing abrasives on the chaining of carbonyl iron powder is analyzed.(2)Shear yield stress model of magnetorheological polishing fluid under magnetic field.The force analysis of the polished abrasive grains in the magnetorheological polishing liquid was carried out based on the close-packed hexagonal structure model.Investigate the holding mechanism of magnetic particles on abrasive particles in magnetorheological polishing,and establish the shear yield stress model of magnetorheological polishing fluid in the absence of flow field.(3)Shear yield stress model of magnetorheological polishing fluid under the combined action of magnetic field and flow field.The influence of flow field on the shear yield stress model after magnetorheological polishing liquid chain is studied by means of simulation and theoretical analysis.Based on the cubic structure model,the holding mechanism of polishing abrasive particles was analyzed,and the shear yield stress model of the magnetorheological polishing fluid under the combined action of magnetic field and flow field was established.(4)The establishment of material removal rate model and experiment.Based on the shear yield stress model of magnetorheological polishing fluid,the material removal rate model under the combined action of magnetic field and flow field is established by considering the magnetic field strength,flow field pressure,workpiece material and workpiece speed in magnetorheological polishing.The magnetic rheological polishing experiment was used to verify the rationality of the model and the analysis.