摘要
大口径光学反射镜的材料选择与研制一直是空间光学系统的主要核心技术,采用凝胶注模成型(Gel-Casting)技术一次性完成1.45m碳化硅反射镜镜坯成型,再经1 700℃反应烧结得到一块完整的碳化硅镜坯。介绍了大口径轻质碳化硅反射镜镜坯的基本结构,系统阐述了SiC反射镜镜坯的制备工艺。结合金相显微镜、XRD物相分析及力学性能测试对SiC镜坯的组织结构进行分析,测试数据表明:1.45m碳化硅反射镜镜坯的密度≥3.0g/cm3,抗弯强度≥330 MPa,弹性模量≥340GPa,轻量化率>74%。碳化硅反射镜镜坯的力学性能均能满足空间光学系统设计的要求。
Preparation of the materials for fabrication of large scale mirrors is the key technology of space optical system.In present work,gel-casting technique is employed to form monolithic silicon carbide mirror with diameter of 1.45 m.After reacting sintering under 1 700 ℃ the RB-SiC ceramic mirror blank is obtained.The general structure of the lightweight SiC mirror blank with large caliber and process route of fabricating the mirror are systematically introduced.Metallographic technique and XRD are applied to microstructure characterization,and the density and mechanical properties of the materials prepared for the mirror are tested.Test results turn out that the density of the RB-SiC reaches 3.0g/cm3,the flexural strength and the elasticity modulus are higher than 330 MPa and 340 GPa,respectively.The rate of weight-lightening is as high as 74%.The RB-SiC mirror fulfills the requirement of the space optical system.
出处
《光学与光电技术》
2014年第6期65-69,共5页
Optics & Optoelectronic Technology
关键词
碳化硅反射镜
轻量化结构
反应烧结
凝胶注浆成型
制备工艺
SiC mirror
lightweight structure
reacting sintering
gel-casting technique
process technology
