摘要: Chemical mechanical polishing is used to polish large area free-standing CVD diamond films with diameters of 66 mm. The influence of polishing plates (iron plate, asphalt plate and soft cushion) and oxidizing agents (K2S2O8 and K2FeO4) on polishing results are investigated. Profilometer (tip radius 5 μm), optical microscope and Raman spectroscopy are used to evaluate the polishing effects of the CVD diamond films. Results show that the material removal rate of iron plate is the highest, while the surface polished by soft cushion is the most uniform with roughness of 2 nm. It is also found that the most effective oxidizing agent is K2FeO4. In conclusion, the optimum polishing conditions are soft cushion and K2FeO4.
摘要: 超声辅助磨削要求超声电源具有稳定的高频输出特性及反应迅速的实时跟踪特性。针对传统超声电源工作频率低、输出功率低、跟踪速度慢等问题,利用STM32F103VET6控制器和直接数字频率合成(direct digital synthesize,DDS)技术,设计并实现专用于超声辅助磨削的具有高频率、高功率和高稳定性的超声电源系统,并采用基于模糊PID(proportion,integral,differential)控制器的频率自动跟踪方法,实现快速准确地频率自动跟踪。使用所设计的超声电源进行电学性能测试及超声辅助磨削加工验证试验,结果表明:所研制的超声辅助磨削专用电源在难加工材料磨削加工中运行良好。