| 摘要 |
A method for forming a thermally stable honeycomb panel which may be used in constructing large mirrors employs thermally stable composite planks comprised of about 50% graphite fibers and of about 50% borosilicate glass. These planks which are formed by hot pressing in vacuum serve as a basic construction material. The thermally stable honeycomb panel is comprised of a core member, a backplate member, and a faceplate member which are bonded by bonding process after a wet frit paste is first applied and then dried to remove volatile solvents. The bonding is completed in an oven in an air atmosphere at a temperature sufficient to melt the glass in the frit paste after the organic binder material is boiled out. After holding the honeycomb panel components at a predetermined temperature for ensuring that all the glass in the frit is melted, the bonded panel is allowed to cool to room temperature. The glass re-soldifies to form bond strengths between the core member, backplate member, and faceplate member which exhibit parent material strength. The thermally stable honeycomb panel has a thermal expansion value in the range from about -5 to about +5 X 10-7 inch/inch/ DEG C. over a range of about 0 DEG C.-300 DEG C.
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