To solve the problems of RB-SiC mirrors in engineering applications, the material preparation, surface modification and aspheric processing of RB-SiC mirrors were analyzed. Firstly, according to the special modification characteristics of the RB-SiC mirrors, a new material whose thermal expansion coefficient was matched well with that of the RB-SiC was chosen to be a new support for the thermal design. Then, the modification and fabrication technologies of RB-SiC mirrors were improved based on the actual situation of the aspheric processing for better processing reliability and shorter processing cycle. Finally, the improvement were verified by experiments. The experimental results indicate that the modified RB-SiC mirror is in a good condition. The RMSs of the mirror surfaces before and after modifications have changed only 0. 017λ(λ=623. 8 nm,change rate in 13%) ,and the aspheric processing time has decreased 1 month or 2 months. The adequate margin of the 10 μm modified layer in the subsequent processing is ensured,the processing security is improved and the process-ing cycle of the aspheric is shortened due to the new technology, which can been applied to the preparation and processing of other aspheric SiC mirrors as well.%针对RB-SiC反射镜工程实践中暴露的一些问题,对RB-SiC反射镜的材料制备、表面改性及非球面加工等技术进行了研究.首先,依据其改性特殊性,选取了与RB-SiC反射镜材料热胀系数匹配的新型支撑材料进行热匹配设计.接着,依据实际工程情况对非球面加工工艺及流程进行技术改进,以提高加工的可靠性.最后,采用试验的方法对RB-SiC反射镜的相关加工方法进行了试验验证.试验结果表明,改性后RB-SiC反射镜完好,改性前后镜面面形精度RMS值变化量仅为0.017λ(λ=623.8 nm),变化率为13％,非球面加工周期缩短了1～2月.该技术确保了RB-SiC反射镜10 μm的改性膜层在后续加工中的加工余量,使其不易被磨漏,提高了加工的安全性,缩短了非球面加工周期,该技术亦适用于其它SiC反射镜的制备及非球面加工.
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