Study On Technique Of Magnetic Polishing And Application Of Free-form Surface Structures Processing

In order to adapt to the rapid development and increasingly fierce competition in the market,the free-form surface structures are widely used in product development in high-tech fields and the demand of surface accuracy and surface quality is getting higher.Polishing technique was the final process in precision and ultra-precision components processing,which restricts the workpiece surface quality,precision and the processing cycle.For the free-form surface structure processing,the current polishing techniques such as chemical mechanical polishing,small tool polishing,and bonnet polishing have the problems that the polishing tool cannot be highly conformed to the free-form surface workpiece,and the high requirement for equipment performance results in high price.The polishing tool in this paper was a flexible magnetic cluster,it had advantages that it can agree with the surface of the workpiece highly and the quality of surface was good after processing,and the demand of equipment was low.Therefore,Magnetic polishing was suitable for ultra-precision machining of free-form surface structures.Based on the basic research of magnetic polishing technology,this paper studied the free surface of microstructure processing.The main contents of this paper as follows:(1)The structure of magnetic polishing tool was designed according to the principle of magnetic polishing and test processing.The effect each component of the polishing fluid on the polishing process was analyzed and the magnetic polishing fluid was prepared by high efficiency formulation.A four axis CNC milling machines and magnetic polishing tool and a magnetic polishing body have been built into the processing test platform.(2)The velocity model of any point in the polishing region was calculated according to the movement way of the polishing tool.The radial pressure distribution model of the polishing area was obtained by testing.And the removal function model was established based on Preston equation.(3)The influences of machining clearance,spindle speed,magnetic field intensity and polishing time on the polishing removal efficiency were analyzed,and the primary and secondary relationships were obtained by orthogonal test.The change of the removal function with the dosage of the polishing fluid was studied experimentally.The multi-head polishing tools were designed in order to improving the processing efficiency,and the whole processing experiment of quartz optical glass was studied.(4)Base on improving the surface quality of the microstructure freeform surface without destroying the three-dimensional shape feature of the microstructure,the study on the conformal polishing of the common microstructure freeform surface was carried out.A comparative study of the removal efficiency about single-headed and multi-headed tools for polishing microstructure workpieces.The application of freeform structure processing was preliminarily realized.