1、前言加工难易程度不仅受加工精度,而且受加工形状特征,加工材质和所用刀具等的影响,因而,“超精密加工”的范围也难以严格规定。目前,可大体将其加工精度范围考虑在10~(-7)～10~(-9)米之内。镜面加工的精度通常要求达到:形状精度0.2微米以下,表面粗糙度0.01～0.02微米,加工表面的平面度至少达到 1, Foreword The degree of processing difficulty is not only affected by the processing accuracy, but also affected by the shape characteristics of the processing, the processing materials and the tools used, etc. Therefore, the scope of “ultra-precision machining” is also difficult to strictly stipulate. At present, the processing accuracy can be generally considered in the range of 10 ~ (-7) ~ 10 ~ (-9) meters. The precision of the mirror processing is usually required to achieve: the shape accuracy of 0.2 microns or less, the surface roughness of 0.01 to 0.02 microns, the processing of the flatness of the surface at least