Research On The Optical Element Fast Polishing Key Technology Based On The Abrasive Wear Mechanism

Optical element has been widely used in laser nuclear fusion deviceastronomical telescope?medical imaging equipment,which involved the national security and defense.At present,high precision and quantity production processing level of optical element in China has huge gap with the advanced countries in the world,and how to carry out high precision and quantity production processing is the core issue of large optical engineering that our country faced.In traditional optical element polishing process,the initial polishing and ring polishing consuming much time can't be satisfied with large optical engineering.Fast polishing technology,with its relatively high material removal rate,has fully replaced initial polishing and part replaced the ring polishing,therefore,it is very urgent to study related content of fast polishing technology.This article embarks from the fast polishing motion model,study and establish the fast polishing technology removal function model based on Preston equation at macro level,and then established material removal microscopic model based on the abrasive wear mechanism at a micro level,in order to reduce the processing time?realize certainty polishing?guarantee the optical element batch production.At the same time,studying the fringe effect in fast polishing,implement the optical element surface precision convergence technology,in order to reduce the optical element surface error.The major research efforts include the following points:1.Relative motion by pad and element is analyzed,fast polishing technology mathematical model of three kinds of motion mode is established.In addition,relative velocity and impact of eccentricity distance on grinding amount are analyzed.2.Velocity distribution model of three kinds of motion mode is established.Based on the ANSYS simulation,pressure distribution model of polishing contact area is established.At last,based on two models established above,fast polishing removal function is established.3.Proceed from the force applied on an particles and numbers of all particles over the wafer-pad contact area to obtain the quantitative mean volume removed by a single particles per unit time and numbers of the active particles over the wafer-pad interface,an optical element fast polishing material removal model is created based on the analysis of fast polishing material removal mechanism.This model is verified correct of the optical element fast polishing technology by orthogonal test.4.Based on fringe effect phenomenon after polishing,in order to reduce the optical element surface error,a method called "sacrifice compensating" is proposed.Based on ANSYS software,influence to contact stress by distribution and number of the compensator and distance from the compensator to optical element is simulated.This model is verified correct by experiment to implement the optical element surface precision convergence technology.