RTV566硅橡胶在航天红外低温镜头中的应用研究

Research on the Application of RTV566 Adhesive in Space Infrared Cryogenic Lens

为了验证RTV566硅橡胶用于航天红外低温镜头的可行性,测试了它的低温力学性能,并开展了基于该胶的试验透镜低温面形测试研究。首先,设计和制作了RTV566硅橡胶拉伸试验件,并通过静力拉伸试验获得了该胶与锗、钛合金的粘接强度及其弹性模量。然后设计并投产了低温透镜试验件。利用RTV566硅橡胶将透镜粘接到镜框内,并在镜框粘接面周围设计柔性结构,且通过ZYGO干涉仪测试透镜的低温面形。拉伸试验结果表明,从常温到180 K时该胶的弹性模量基本没有变化,其平均值约为6 MPa;剪切强度和拉伸强度在从常温到200 K时基本没有变化,到180 K时有一定的增加。透镜组件的低温面形测试结果表明,从常温到200 K时平面面形基本没有变化,其精度优于1/30λ(λ=0.6328μm)。这说明卸载结构和RTV566硅橡胶的共同作用很好地卸载了热应力,保证了透镜面形。本文的研究工作表明,RTV566硅橡胶可用于200 K及以上的空间红外低温镜头支撑结构。

In order to verify the application feasibility of RTV566 adhesive in space infrared cryogenic lens, the low temperature mechanical properties of RTV566 are tested, and the low temperature surface shapes of the experimental lens based on RTV566 are tested and studied. Firstly, RTV566 adhesive tensile test samples are designed and manufactured. And the bonding strength with germanium and titanium alloy, as well as the elastic modulus of the adhesive are obtained through static tensile test. Then the cryogenic lens test sample is designed and put into production. RTV566 adhesive is used to bond the lens into the frame, and a flexible structure is designed around the adhesive surface of the lens frame. The low temperature surface shapes of the lens are tested by ZYGO interferometer. The tensile test results show that the elastic modulus of the adhesive almost does not change from room temperature to 180 K, and the average value approximates to 6 MPa.The shear and tensile strength almost do not change from room temperature to 200 K, but increase at 180 K. The test results show that the surface shape of the lens almost does not change from room temperature to 200 K, whose accuracy is better than 1/30λ(λ=0.6328μm).It indicates that the flexure structure and RTV566 adhesive reduce thermal stress, and ensure the surface shape of the lens. The research in this paper shows that RTV566 adhesive can be used in the support structure of space infrared cryogenic lens at 200 K and above.