针对非球面光学元件连续变曲率的特点,提出了一种基于平面抛光斑演变获取非球面磁流变抛光去除函数的技术思路.通过分析磁流变抛光机理,建立了磁流变抛光多因素耦合作用模型.基于该模型提出磁流变抛光去除函数获取的微分解耦方法,实现对抛光斑形成机制中的几何因素解耦,发现当工艺条件变化较小时,在空间中的特定点处,去除效率的变化量与工件浸入深度的改变量呈线性关系.实验观测的20个点中,有17处决定系数在90%以上,另外3处在80%以上,峰值去除率和体积去除率演变的决定系数分别达到92%和94%,实验验证了这一结论.

This paper proposes a new approach to obtain the magnetorheological finishing(MRF) removal function based on the spot in plane geometry,especially for aspheric optics whose curvature changes successively.With research of the mechanism of MRF,the multi-factor interaction model is established,with which the Differential Decoupling Method(DDM) for procuring MRF spot is developed.The DDM is used to decouple the geometry factor from the complicated factors that determine the MRF process.The DDM indicates that the variation of removal rate changes linearly with the variation of immersion depth.In the 20 experimental locations,good coefficients of determination are found,with 17 locations above 90% and 3 above 80%,respectively.Besides,the figures for transition of peak removal rate and volume removal rate reach 92% and 94% respectively,experimentally confirming our conclusions.