Modeling And Experimental Study Of Contact Surface Between Workpiece And Polishing Pad In Continuous Polishing

The inertial confinement fusion(ICF)engineering points out the direction for solving the energy problem completely with the energy crisis intensifying.However,the speed of inertial confinement fusion devices in china is greatly limited by the supply shortage of large aperture planar components.Continuous polishing is widely used because of its full frequency error control ability and the high price of the planar element,but the long cycle and high cost brought by blurry element surface evolution mechanism and process instability is the weakness.Therefore,the mechanism of the processing parameters in the process of polishing contact state needs to be studied systematically and the processing mechanism is of great significance to solve the contradiction between the efficiency and the quality of the existing process.The physical properties of the optical components,the functional properties of the optical disk and the abrasive grains in the polishing liquid are introduced to characterize the contact interface.Then,the frequency conversion scanning experiment of polishing pad shows that the elastic response of the polishing pad is dominant in the process of contact.The establishment of the removal model of single particle is based on elastic-plastic contact mechanics,analysing the average size of polishing abrasive invasion depth and hydrolysis layer thickness respectively.Then,the effective wear particle number is obtained under the assumption of uniform distribution of abrasive grains at the contact surface to obtain the full aperture average material removal rate.Finally,the model is compared with the classical preston equation,explaining the parameter in the preston equation.The critical pressure of the material removal rate mutation is explained from the microscopic point of view with the previous experiments.In the modeling of static contact for contact pairs,firstly,the interface response mechanism of the static contact pairs is determined by uniaxial compression test,which is elastic response.Then,the interface stress distribution is obtained by contact Lagrange algorithm and symmetric contact under different contact conditions due to the polishing pad surface error.Finally,the preparation of the workpiece((37)50mm?5mm)-polishing pad((37)80mm?7mm)contact pairs to measure the real contact area and stress distribution by fujing pressure film.The evolution of element surface is based on the preston equation to establish single point material removal model.The evolution of workpiece’s figure under uniform stress is mainly the contribution of velocity field to material removal rate.The influence of eccentricity on the convergence speed of element figure is studied and compared with the experiment.The evolution of workpiece’s figure under non-uniform stress is based on the data obtained by dynamic contact simulation,and the surface evolution of element is studied by the iterative calculation of the model of single point material removal rate.Finally,the method of improving the surface evenness of the component by means of putting weight block is put forward aimed at the component edge.