Composite mirror blank material for ceramic-based space mirror

Abstract

The invention belongs to the technical field of preparation of low-expansion glass and provides a composite mirror blank material for a ceramic-based space reflecting mirror. The composite mirror blank material for the ceramic-based space reflecting mirror, provided by the invention, is prepared from aluminum oxide ceramic and a glass glaze surface, wherein the aluminum oxide ceramic is corundum ceramic with Al2O3 which is greater than or equal to 99.0 percent; the glass glaze surface is sealed on the surface of the aluminum oxide ceramic; the glass glaze surface is borosilicate glass; the expansion coefficient of the borosilicate glass is lower than that of the aluminum oxide ceramic; the expansion coefficient difference deltaalpha between the aluminum oxide ceramic and the borosilicate glass in a range of 20 to 400 DEG C is less than or equal to 0.5*10<-6> / K. According to the glass material provided by the invention, the disadvantages of a ceramic material under film plating conditions can be overcome through the easiness for polishing and structure density; the smooth finish of the polished glass can meet conditions of plating a film by higher reflectivity; the composite mirrorblank material for the ceramic-based space reflecting mirror has the advantages of simple manufacturing technology and no shrinkage; large-size and large-batch production can be realized and a lot ofcost is reduced.

Description

technical field [0001] The invention belongs to the technical field of preparation of low-expansion glass, and mainly relates to a composite mirror blank material for a ceramic-based space mirror. Background technique [0002] With the intensification of competition in the space field, countries attach great importance to the development of related technologies. One of the main functions of space vehicles is to collect information. Reflectors are the core components of space astronomical optical instruments, and their comprehensive performance directly affects the performance of instruments. Imaging quality, service life, instrument quality, etc., so it is of great significance to the performance of the space optical system. The design trend of space telescope primary reflectors is large area and low specific gravity, and the reflectors are required to have excellent mechanical properties and thermophysical properties. Generally speaking, the greater the thermal expansion c...

AI Technical Summary

Problems solved by technology

However, glass materials have disadvantages such as high brittleness and poor rigidity, which limit their application and development.

[0008] Alumina ceramics are usually not selected as the material of the mirror blank, because the ceramic itself has many defects, and there are still a large number of micropores on the polished surface, resulting in excessive roughness, which makes it impossible to obtain a reflectivity that meets the requirements

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