【作者】 张超；

【导师】 金滩； 樊利军；

【作者基本信息】 湖南大学 ， 机械工程（专业学位）， 2018， 硕士

【摘要】 大口径光学平面玻璃元件是激光核聚变系统(ICF)的核心部件,为保证激光打靶的准确性和系统的安全性,人们对光学玻璃的加工精度有着严苛的要求。环形抛光具有良好的全频谱均匀去除能力、加工精度高和生产成本低等特点,使其成为大口径光学元件加工的首选方式,但是我国的环抛技术严重依赖操作者的经验,加工效率低下,究其原因是对抛光过程中工件材料去除的规律、抛光工艺参数对抛光面形的影响规律认识不够。本文基于环形抛光加工技术,研究了 BK7光学平面玻璃的材料去除量,进一步实验,建立了材料去除率数学模型,将其用于加工分析,优化环抛加工工艺,最终用于Φ300×28mm的大口径BK7光学玻璃的抛光加工,主要内容如下:1)在环形抛光机床上以抛光盘转速、抛光压强为实验变量,对BK7光学玻璃的材料去除量及抛光后的工件表面质量进行了研究。结果表明:工件材料去除量是和抛光速度、抛光压强成正比的;抛光压力的增大,工件表面容易出现划痕。2)在前面实验的基础上,进一步研究了 BK7光学玻璃的抛光材料去除率,提出了一种工件抛光表面高度绝对变化量的测量方法,并建立了基于Preston方程的BK7光学玻璃材料去除率数学模型。3)在主动式环形抛光机床上,研究了转速比、工件偏心距、修正盘偏心距这些抛光参数与BK7光学玻璃抛光面形的关系,结合前面的理论对实际抛光加工进行了分析和指导。并加工出了面形PV值为0.09λ和PV0.2λ(λ=632.8nm)的高精度面形的BK7光学玻璃(Φ100mm)。4)通过前面章节的理论和工艺实验,对直径300mm的BK7光学玻璃进行抛光加工,成功达到了加工要求。针对抛光过程中,工件出现的“塌边”现象,通过对抛光接触区域的压强进行仿真,以抛光压强的角度对其进行了解释,并发现在工件表面进行加载可以有效的降低工件材料去除的不均匀性。更多还原

【Abstract】 Large aperture planar optical glass components are widely reguired in the Inertial laser Fusion(ICF)system.In order to ensure the precision of laser targeting and system security,stringent requirements on the processing of optical glass have been made.Continuous polishing(CP)has been the primary method to polish Large aperture optical planar glass for its full spectrum evenly removal ability,high polishing accuracy,and low production cost.But the continuous polishing technology of our country relies heavily on technician’s experience.which lowering the fabrication efficiency severely.The key reason is that we do not clear about the laws of material removal rate in the process of polishing and the fabrication parameters’ effect on the polished optical surface.In this thesis,the material removal volume of BK7 optical planar glass was studied,and based on this,the material removal rate of BK7 optical glass was further studied,and the mathematical model of its material removal rate was established.The technological parameters were optimized with the guidance of the material removal rate mathematical model.The BK7 optical glass with a diameter of 300 mm was fabricated with the guidance of previous theory and technological experiments,the main content is as follows:1)The material removal volume and the polished surface quality of the of BK7 optical glass were studied in the continuous polishing machine with the polishing disc revolution speed and the polishing pressure as experimental variables.2)On the basis of previous experiments,the material removal rate of BK7 optical glass was further studied,and based on Preston equation,the mathematical model of its material removal rate was established.3)The effects of revolution speed ratio,workpeice eccentricity and conditioner eccentricity on the polished surface of BK7 optical glass were studied in the active continuous polishing machine.The process of polishing was analyzed and improved with the previous theory.and ultra-precision polished surface of BK7 optical glasses(Φ100mm)were fabricated with PV value of 0.09λ and 0.2λ(λ=632.8nm).4)The BK7 optical glass with a diameter of 300 mm was fabricated with the guidance of previous chapters’ theory and technological experiments,and the processing requirement was reached successfully.Aiming at explaining the phenomenon of "collapse" of the workpiece during the polishing process,the pressure in the polishing contact area was simulated,and found that the inhomogeneity of the workpiece material removal volume can be reduced effectively by loading on the back of the workpiece.更多还原