全低温非球面系统微晶元件制造的工艺基础研究

Because cryogenic optical system ( the optical system is placed in low temperature environment) can effectively reduce the infrared radiation of background, prolong the integration time of infrared detector, reduce the noise of infrared detector, and improve the background limited detectivity of infrared detector, so it is important and irreplaceable in the deep-space science detection and national defense anti-missile early warning, etc. The manufacturing technology of optical element and same material structure parts is one of the key difficulties technique in realizing the cryogenic optical system, and super low inflation glass-ceramic is one of the important material to cryogenic optics system, the project studies the stress relief mechanism and stress relieving method of glass-ceramic optical element and structure parts, studies acid corrosion mechanism and conformal acid corrosion technology of glass-ceramic parts, and studies the manufacturing technology of lightweight aspheric double mirror glass-ceramic optical element and lightweight glass-ceramic system structure parts. The research results will provide manufacturing technology foundation of glass-ceramic parts of cryogenic optical system, and the research results can also be used to other brittle glass component's manufacturing. It will have important significance to the development of space cryogenic optical system which is in urgent need in our country.

由于全低温光学系统（即把光学系统整体置于低温环境中）可有效减少背景的红外辐射，从而延长探测器积分时间，减小光子噪声，提高探测器背景限探测率，因此其在深空科学探测、国防反导预警等方面作用重大，不可替代。光学及结构一体零件和同材料结构件的制造是全低温光学系统能最终实现的关键难点之一。针对全低温光学系统的可选重要材料超低膨胀微晶玻璃,项目研究微晶零件的应力消除机理及应力消除方法、酸蚀机理和保形酸蚀工艺、高精度微晶轻量化非球面双面反射镜结构一体件和系统轻量化结构件的制造工艺，项目将为全低温微晶光学系统的发展应用提供元件制造工艺基础，成果也可用于其它脆性玻璃元件制造，其对我国急需发展的空间全低温光学系统具有重要意义。

全低温光学系统（即把光学系统整体置于低温环境中）在深空科学探测、国防反导预警等方面作用重大，不可替代。光学及结构一体零件和同材料结构件的制造是微晶全低温光学系统能最终实现的关键难点之一。项目研究了微晶零件铣磨过程中残余应力的产生原因、酸蚀去应力机理和保形酸蚀工艺、高精度微晶轻量化非球面双面反射镜结构一体件和系统轻量化结构件的制造工艺。通过研究项目得到微晶玻璃磨削残余应力最主要是磨粒与工件之间的机械作用，磨粒机械作用主要体现在磨粒对工件具有磨削力作用，并且磨削残余应力主要分布在表面缺陷层、亚表面裂纹层及裂纹尖端，越接近裂纹尖端，残余应力越大；随磨削深度、工件进给速度的增大，铣磨砂轮砂粒的增大，产生的残余应力增大，随砂轮转速转速增大，产生的残余应力会变小，通过优化铣磨工艺可显著减小残余应力；酸蚀使表面裂纹及微裂纹开口端的去除速度大于其尖端的速度，使裂纹尖端的曲率半径增大，从而改变了应力集中区的微观结构使微晶玻璃表面的残余应力得以释放；项目实验优化了酸蚀工艺，实现了保形酸蚀(保形酸蚀就是经过酸蚀工艺后基本不改变工件的形位公差，从而使经过酸蚀工艺后的微晶非光学面外形不再需要磨削加工)；项目编制并优化工艺研制了满足全低温系统要求的Φ333mmx82mm微晶镜间结构样件和Φ333mm侧面有轻量化孔的非球面双面反射镜结构一体样件，项目能为全低温微晶光学系统的发展应用提供元件制造工艺基础，成果也可用于其它脆性玻璃空间反射镜元件制造，能促进我国空间光学系统的发展。