强光光学零件磁流变抛光误差的频谱特征与演变研究

Spectral Feature and Evolvement of Machining Error of High-power Optical Elements in Magnetorheological Finishing

通过分析磁流变抛光的材料去除特征、误差功率谱密度的定量计算方法、敏感频率误差的演变规律,探索误差频谱与去除函数、走刀方式、走刀步距等加工参数的对应关系,为工艺过程的合理控制提供指导。典型强光光学零件磁流变抛光的实验结果表明,通过优化工艺参数,能够大幅修正低频误差、控制中高频误差,保证0.03～8.3mm-1频段误差全部满足NIF评价指标要求。

By analysis of the removal characteristics of surface material, the calculating algorithm for power spectral density(PSD) and the evolving rule of sensitive frequency error are studied, the corresponding relation between the error spectrum and the figuring parameters including removal function, feed way and feed spacing, the work helps to control the surface error of high-power optical elements. The effectiveness of evaluation method is experimentally verified in the figuring process of typical high-power optical element by using MRF technology. The low frequency errors are corrected and the medium-high frequency errors are controlled by optimizing the figuring parameters. All errors in 0.03~8.3 mm-1 frequency range satisfy the NIF evaluation requirements.