Theoretical And Experimental Study On Parabolic Lapping Of Stationary Abrasive

With the continuous progress of science and technology,people have higher and higher requirements for the accuracy of workpiece surface,such as better surface precision,lower roughness,faster processing efficiency and so on.For the traditional plane and spherical lapping,there are relatively mature lapping processes for both large and small diameter workpiece,but the plane and spherical lapping has been unable to meet the manufacturing requirements of many workpiece,Therefore,it is an important task to explore a high precision,high efficiency and low cost aspheric surface processing technology.Parabolic lapping with solid abrasive is a new method of parabolic processing.In this paper,the lapping mechanism of solid abrasive parabolic lapping was firstly studied,starting from the micro-morphology of the abrasive particles,the contact state between the abrasive particles and the workpiece is assumed,According to the force state of paraboloid lapping,the pressure distribution on the workpiece surface and the change law of lapping relative speed were summarized,and the calculation method of driving torque was obtained,which provided a basis for the design and manufacture of lapping tools.Then,from the perspective of a single lapping particle,the influence of lapping process parameters on material removal rate and surface roughness was discussed,and a theoretical prediction model was established,The removal rate and surface roughness of the workpiece with different hardness were simulated by computer aided software,and the influence trend of each technological parameter on the removal rate and surface roughness was obtained.Finally,based on the theory of shape preserving wear of abrasive tools,the distribution law of upper pellets of abrasive tools is deduced,The Design Exploration system in ANSYS Workbench was used to optimize the distance between the belts,so as to obtain the lapping tool system meeting the requirements,and conduct lapping test with the optimized lapping tool,by comparing the testal results with the theoretical prediction results,it can be concluded that: Parabolic lapping of solid abrasive is feasible.The theoretical prediction model can predict the change trend of material removal rate and surface roughness,That is,the material removal rate of solid abrasive parabolic lapping is proportional to the spindle speed and the 5/4 square of lapping pressure,and inversely proportional to the 1/4 square of lapping particle concentration;The surface roughness is directly proportional to the size of the abrasive particle and the 1/2 square of the lapping pressure,and inversely proportional to the 1/2 square of the lapping particle concentration,while the lapping machine spindle speed has little effect on the surface roughness.