碳化硅表面硅改性层的磁介质辅助抛光

为了实现碳化硅表面硅改性层的精密抛光，获得高质量光学表面，对磁介质辅助抛光技术进行研究。设计了适合碳化硅表面硅改性层抛光的磁介质辅助抛光工具，并对抛光工具的材料去除函数进行研究。针对材料去除函数的特性，对数控磁介质辅助抛光的驻留时间算法进行了研究。采用磁介质辅助抛光技术对碳化硅表面硅改性层平面样片进行了抛光实验。经过一次抛光迭代，碳化硅样片表面硅改性层的面形精度(均方根)由0.049λ收敛到0.015λ（λ=0.6328 μm），表面粗糙度从2 nm改善至0.64 nm。实验结果表明基于矩阵代数的驻留时间算法有效，磁介质辅助抛光适合碳化硅表面硅改性层加工。

Magnetic-Medium Assistant Polishing of Silicon Modification Layer on Silicon Carbide Surface

To actualize precise polishing of silicon modification layer on silicon carbide surface, and achieve high-quality optical surface, a technology of magnetic-medium assistant polishing is studied. The special magnetic polishing tool for polishing silicon modification layer on silicon carbide surface is designed, and the material removal function of magnetic polishing tool is studied. On the basis of the material removal function, the dwell time algorithm of computer-controlled magnetic-medium assistant polishing is researched. A Si-modified on silicon carbide surface experimental sample is polished by magnetic-medium assistant polishing technology. Initial figure error and roughness of the sample are 0.049λ（λ=0.6328 μm) (root-mean-square) and 2 nm. After one polishing iteration, the figure error and roughness of the sample are 0.015λ（λ=0.6328 μm) and 0.64 nm, respectively. Experimental results indicate the dwell time algorithm based on matrix algebra is effective, and magnetic-medium assistant polishing is appropriate for polishing silicon modification layer on silicon carbide surface.