【作者】 林涛；

【导师】 杨炜；

【作者基本信息】 厦门大学 ， 机械工程， 2017， 硕士

【摘要】 光学元件在激光核聚变装置、天文望远镜、医疗影像设备等涉及国家安全与国防领域中得到广泛的应用,目前我国光学元件的高精密及批量化加工水平与世界先进国家之间还有差距,而如何进行大批量的高效精密加工,是我国大型光学工程所面临的核心问题。在传统光学元件抛光加工流程中,初抛与环抛所耗时间最多,不能满足大型光学工程的需求,快速抛光技术以其相对较高的材料去除率,已经全面取代了初抛,部分取代了环形抛光,因此,研究快速抛光技术的相关内容刻不容缓。本文从快速抛光运动模型出发,宏观上,研究并建立了基于Preston方程的快速抛光技术去除函数模型,微观上,基于磨粒磨损去除机理建立了材料去除微观模型,以期减少抛光加工时间,实现确定性抛光,保证光学元件批量生产:同时研究了快速抛光中元件的边缘效应,实现了光学元件面型精度收敛的控制技术,以此降低光学元件面型误差。本论文研究内容包括以下几点:1.分析了快速抛光光学元件和抛光盘的相对运动,建立了快速抛光技术三种运动方式下的数学模型,同时对快速抛光光学元件半径上各点的相对速度和偏心距对材料去除率影响进行了分析。2.建立了快速抛光技术三种运动方式下的速度分布模型,基于ANSYS仿真建立了接触区的压力分布模型,根据所建立的速度和压力分布模型得到了三种运动模型下的去除函数模型。3.分析光学元件快速抛光材料去除机制基础上,从单颗磨粒受力和抛光垫峰点捕获的磨粒数出发,获得量化的单颗磨粒瞬时切除体积和抛光区介入去除材料的磨粒数,从而建立一种快速抛光材料去除模型。通过正交实验,验证了所得到的光学元件快速抛光材料去除模型的正确性。4.针对光学元件抛光后边缘效应现象及成因,提出“牺牲补偿式”加工方法改善光学元件面型,基于此方法,通过ANSYS软件分别就补偿片分布方式及个数、补偿片与光学元件之间距离对光学元件表面应力峰值和最低值的影响情况进行仿真,经过实验证明所建立模型是正确的,实现元件面型精度控制技术。更多还原

【Abstract】 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.更多还原