轻量化碳化硅反射镜古典光学加工研究

Classical Optical Processing of Lightweight Silicon Carbide Mirror

介绍了一类轻量化碳化硅反射镜的古典光学加工方法。其中精磨阶段,应用金刚砂和碳化硼分别对镜体进行了精磨试验。结果表明,在相同精磨时间下,碳化硼散粒磨料(240#)的磨削量至少比金刚砂散粒磨料大0.01 mm,切削效果明显优于金刚砂散粒磨料,并形成载荷50 N,主轴转速45 r/min的精磨最佳工艺参数;抛光阶段,以柏油抛光模为基底,分别使用氧化铈抛光液和钻石液对镜体进行抛光,结果表明钻石液可有效改善零件的面形和表面质量,并形成载荷为30 N,主轴转速为60 r/min的抛光最佳工艺参数。分别使用W1和W0.3两种粒度的钻石液对镜体抛光,可使镜体面形最佳达到低光圈3道,表面光洁度良好,无明显路子与亮点。由于镜体结构的特殊性导致其抛光难度较大,继续应用环形抛光机对镜体进行无应力抛光,修改镜体局部不规则度,最终零件不规则度可满足1道光圈。

A classical optical processing method for a class of lightweight silicon carbide mirrors is presented.In the fine grinding stage,the mirror body is subjected to fine grinding experiments with emery and boron carbide respectively.Results show that under the same fine grinding time,the grinding amount of the boron carbide granular abrasive(240#)is at least 0.01 mm larger than that of the emery granular abrasive,and the cutting effect is obviously better than that of the emery granular abrasive,the best process parameters for fine grinding is with a load of50 N and a spindle speed of 45 r/min.In the polishing stage,using the asphalt polishing mold as the base,the mirror body is polished with cerium oxide polishing liquid and diamond liquid respectively.Results show that the diamond liquid can effectively improve the surface shape and surface quality of the parts.And the optimal process parameters for polishing is with a load of 30 N and a spindle speed of 60 r/min.The mirror body is polished with diamond liquid with two particle sizes of W1 and W0.3 respectively,which can make the mirror body surface best reach 3 low apertures,the surface finish is good,and there are no obvious paths and bright spots.Due to the particularity of the structure of the mirror body,it is difficult to polish the mirror body.A ring polishing machine is used to polish the mirror body without stress and modify the local irregularity of the mirror body.The irregularity of the final part can meet one aperture.