目的 研发一种高精高效单晶碳化硅表面抛光技术。方法 采用电磁场励磁的大抛光模磁流变抛光方法加工单晶碳化硅，利用自制的电磁铁励磁装置与磁流变抛光装置，进行单因素实验，研究电流强度、工作间隙和抛光时间等工艺参数对单晶碳化硅磁流变抛光加工性能的影响，并检测加工面粗糙度及其变化率来分析抛光效果。结果 在工作间隙1.4 mm、电流强度12 A的工艺参数下，加工面粗糙度值随着加工时间的增加而降低，抛光60 min后，加工面粗糙度值Ra达到0.9 nm，变化率达到98.3%。加工面粗糙度值随通电电流的增大而减小，随着工作间隙的增大而增大。在工作间隙为1.0 mm、通电电流为16 A、加工时间为40 min的优化参数下抛光单晶碳化硅，可获得表面粗糙度Ra为0.6 nm的超光滑表面。结论 应用电磁场励磁的大抛光模盘式磁流变抛光方法加工单晶碳化硅材料，能够获得亚纳米级表面粗糙度。

The work aims to develop a high precision and efficiency polishing technique for single-crystal silicon carbide surface. Single crystal silicon carbide was polished by a magnetorheological polishing method using a large polishing tool excited by an electromagnetic field. The self-developed electromagnet excitation device and magnetorheological polishing device were used for single-factor experiments. Effects of process parameters such as current intensity, working gap and polishing time on polishing performance were studied. The roughness of polished surface and its rate of change were analyzed to investigate the polishing effect. Under the process parameters of working gap of 1.4 mm and current strength of 12 A, the roughness value of the polished surface decreased with the increase of polishing time. After 60 min, the roughness value of the polished surface reached Ra 0.9 nm, and the rate of change reached 98.3%. The roughness of the polished surface decreased with the increase of the current, and increased with the increase of the working gap. Under optimized parameters of the working gap of 1.0 mm, the energized current of 16 A and the processing time of 40 min, an ultra-smooth surface of single crystal silicon carbide was obtained with surface roughness of Ra 0.6 nm. The sub-nanometer surface roughness of single crystal silicon carbide materials can be obtained by the method of magnetorheological polishing using large polishing tool excited by electromagnetic field.