Develop Grinding And Polishing Equipment And Basic Study On Magneto-rheological Finishing For Conformal Optics Dome

Conformal optics dome has been becoming one of the indispensible parts in precise homing arms and increasingly takes great role in the field of military affairs for its figure can minish resistance coefficient so as to enhance cannon-shot and velocity and to reduce the time of aviation. One of the material widely used in missile dome is magnesium fluoride processed by high temperature and high pressure, which has a great of excellence such as high permeance coefficient in middle infrared, low hot-radiation, dispersion and double-refrangibility, high intensity and mechanics capability, and can bear or endure high temperature, hot impact and erosion from acid, alkali and water. MRF, a novel machining method developed years ago, is one of the dominate method in exceed precision process for its high precision, a bound of machining object and no damnification in sub-surface of part. So, to polish conformal optics dome of magnesium fluoride by MRF, the following works has been done in this paper.Firstly, the equipment of grinding and MRF is designed according to the dimension of conformal optics dome. Inherence frequency and shake model are obtained by analyzing the modal of the machine tool and the error model is derived by the utilization of the theory of multi-body system, which are the basements for getting high precision conformal optics domes.Secondly, the requirements for magneto-rheological fluid to polish MgF2 are analyzed. Magneto-rheological fluid is put up after choosing appropriate polishing powder by examinations. Then the performances of our magneto-rheological fluid are tested. It is proved that the above magneto-rheological fluid can meet MgF2's polishing need.Thirdly, based on MgF2, the rule of polishing quality and efficiency waving with the processing parameters is analyzed. And then, the processing parameters were optimized according to the gray relational analysis, with which upper polishing efficiency and lower surface roughness are obtained. Finally, for the curvature of conformal optics dome surface is continuum variation, the removing function model of polishing protruding spherical by MRF is analyzed in theory. Then the actual removing function is studied though examination and the stability of removing function is analyzed by polishing several spots. At last, the different of spots on plane and on protruding spherical and reasons leading to these difference are given.