REFLECTING MIRROR AND PRODUCTION METHOD THEREFOR

PROBLEM TO BE SOLVED: To obtain a reflecting mirror which is composed of a carbon fiber-reinforced silicon carbide (C/SiC) composite material, enables surface polishing to be applied to the mirror finished surface roughness thereof required as a reflecting mirror, is high in strength, high in rigidity, low in thermal expansion, and light in weight, can be made large-sized and is suitable for IR telescopes for space and ground, etc. SOLUTION: The reflecting mirror is obtained using a C/SiC composite material composed of reinforcing carbon fibers and silicon carbide matrix, wherein the carbon fiber substrate as the raw material of the C/SiC is composed of pitch-based and PAN-based short carbon fibers. By using the fiber substrate of such constitution, the promotion of the reaction of silicon and the PAN-based carbon fibers in impregnation of the C/C substrate (intermediate product) with the silicon is made possible and as a result, the SiC ratio in the C/SiC composite material for the reflecting mirror is increased and the homogeneous distribution of constituents, such as the fibers is achieved and the strength and the mirror finished surface roughness are improved. As a result, the weight reduction and large sizing can be realized. COPYRIGHT: (C)2006,JPO&NCIPI