Study On Stability Improvement And Path Optimization In Numerical Control Small Tool Polishing For Optical Component

Numerical control small tool polishing is widely used in modern optic fabrication. It plays an important role in connecting the grinding and high accuracy finishing process like magnetorheological finishing or ion beam figuring, based on its advantages like fine shaping ability, low cost and so on. But it also has its own shortages,such as unstable material removal function, sub-surface damage and edge effect, which limit its development seriously. It is urgent to raise the stability and error restraint ability to reduce the polishing time and make contribution to the final figure accurary of optical component. There has been a number of relevant research,but they are not so valuable. This paper focuses on the common polishing tool pitch. As to the removal mechanism, several well-accepted models are analyzed to predict the key factor of optical polishing pitch-penetration. Combined with slurry jet-feed system to control the polishing temperature, remarkable polishing stability progress is made. A pseudo-random tool path is put forward to take the place of traditional path to restrain the PSD peak. Both the two ways have been proved by experiments to improve the ability of small tool polishing effectively.The research work includes:(1) Based on the material removal models and property of common modified pitch, a penetration test is ameliorated to study the optical pitch and some laws are found to be useful;(2) According to the results of penetration test, temperature is carefully set to compare the difference of pitches. The key data like removal rate and surface roughness is studied to better understand the removal mechanism and optical polishing pitch;(3) A strategy coming from the penetration curve is put forward and experimentally proved. The life of polishing pitch has been prolonged for one more time. More stable polishing process and higher figure accurary have been realized;(4) A pseudo-random tool path is introduced in details based on the principle of entropy. Entropy is calculated to be a reference to evaluate different paths. Analysis is done in the aspects of degree of freedom and pace. Technical advantage of pseudo-random tool path is achieved by several experiments.