Study On Carbon Fiber/Cyanate Composite For Space Optical Mirror

Thedevelopmentof space exploration technology requires the improvement of detection precision,the effective way is to increase the diameter of space optical mirror,which means more weightof the mirror and the increasing of costs and difficulties of launch.Traditional primary mirror materials such as glass,metaland ceramic cannot meet the requirements gradually.To solve this problem,adopting more reasonable materialsto design the lightweightspace optical mirror becomes an urgency.In this paper,carbon fiber/cyanate composite material is used as the lightweight primary mirror material.First of all,the resin matrix satisfied the requirement of the space structure is prepared by modifying the cyanate ester resin,and the impact strength reaches 16.4KJ/m2,the bending strength is 127MPa,the tensile strength is 73MPa and the elongation at fracture is 3.4%.Compared with traditional epoxy resin,the ability of moisture absorption is reduced by 83%?85%;Secondly,after designing the layer of carbon fiber/cyanate composite,the composite achieves quasi-zero expansion state,the elastic moduli of 0°and 90° laminatesare respectively82.1 GPa and 76.3GPa,the thermal expansion coefficientsare respectively 0.78x10-6 and 0.95×10-6.After radiated,the mechanical performance of carbon fiber/cyanate composite has been saved more than 84%,which means that the property of radiation resistance is excellent.Compared to carbon fiber/epoxy composite,the interlayer shear strength of carbon fiber/cyanate composite has increased by 35%.The vacuum gassing and moisture resistance of carbon fiber/cyanate composite can satisfy the requirement of space optical mirror and is much better than carbon fiber/epoxy composite.Then,technologies of hot-melt prepreg and compression molding are studied,and the billet of lightweight space optical mirror is prepared,the diameter is 300mm,the height is 50mm,the wall thickness is 4mm and the weight is 3.1kg,which is 48%lighter than SiC mirror.Finally,the technology of nickel plating on the surface of carbon fiber/cyanate composite is studied.A nickel layer is plated on the surface of lightweight composite mirror successfully,and the thickness of nickel layer is 0.1mm,and the layer is well combined with composite matrix without separation,which means the layer can satisfy theworking demand of space optical mirror.In this paper,the matrix of carbon fiber/cyanate composite is studied,the structure of carbon fiber/cyanate composite is designed,the prepreg of carbon fiber/cyanate composite is prepared,the molding process of carbon fiber/cyanate composite is researched,and the technology of nickel plating on the surface of carbon fiber/cyanate composite is studied.With all of these,lightweight space optical mirror is prepared.