磁流变加工对中频误差的影响

摘要

Experiments on magnetorheological finishing (MRF) were carried out to remove the subsurface defect (SSD) layer left by conventional polishing. The simulation and experiment results show that, the scanning interval of MRF will lead to the mid-spatial frequency error of corresponding frequency, the unstability of the polishing spot will leave the mid-spatial frequency error of uncertain frequency, and an approximately linear correlation is found between the depth of removal and the peak value of power spectral density (PSD) of processed components. With MRF as the method to remove the SSD layer, the quality of processed components concerning the mid-spatial frequency is greatly affected by the processing settings. If a thick SSD layer is left by an inappropriate prior polishing, the PSD after MRF will exceed the limit.%基于传统抛光的亚表面损伤层厚度,进行磁流变去除亚表面损伤层的实验以便验证在该加工方式下对元件中频误差的影响.计算机模拟结果及实验数据表明:磁流变加工的走刀间距会引起中频误差评价指标PSD曲线出现对应频率的峰值;抛光斑的不稳定性会引起PSD曲线出现不确定的次主峰；去除深度与PSD曲线峰值之间有近似的线性关系.采用磁流变作为亚表面损伤层的去除手段,元件的中频误差质量受加工参数影响很大.如果前级加工不佳导致留下的亚表面损伤层较深,用磁流变加工进行去除时会造成中频误差质量超过限定指标.