Study on Ultra-precision Grinding Machining of Optical Aspheric Surface in Ductile Mode

摘要

In this paper, in order to grind Optical aspheric surfaces with high quality and high precision, some factors that influence the roughness and profile accuracy of machined surfaces were theoretically analyzed. At the same time, all kinds of parameters of ultra-precision grinding optical aspheric surface in ductile mode were optimized. Afterwards author developed the ultra-precision aspheric grinding system. It's principal axis of the workpiece, traverse guide, longitudinal guide and principal axis of the grinder were aero-static bearing form. Turning accuracy of principal axis of the workpiece was 0.05μm. The highest rotate speed of the grinder was 80000rev/min. It's turning accuracy was 0.1μm. The resolution of linear displacement of the traverse and longitudinal guide was 4.9nm. Micro-adjusting accuracy of the center high micro-adjusting machine of the grinder was 0.1μm. Finally, we performed grinding aspheric surface experiments on this grinding system. The results show that to obtain high accuracy and high quality aspheric surface, the mean size of grains of diamond wheels should smaller than 10μm, and also the higher speed to the wheel and small feed rate are needed. After optimizing these grinding parameters, the final machined aspheric profile accuracy can reach 0.4μm and surface roughness can be less than 0.01μm.