LIGHTWEIGHT MIRROR STRUCTURES

OVER THE PAST DECADE THERE HAS BEEN AN EVER INCREASING NEED FOR LARGE, LIGHTWEIGHT, STIFF OPTICAL STRUCTURES FOR SPACE APPLICATION. RESIN MATRIX COMPOSITE WHICH SEEMED THE IDEAL CANDIDATE MATERIAL HAS POOR DIMENSIONAL STABILITY DUE TO ITSPROPENSITY TO ABSORB WATER VAPOR ON EARTH AND LOSE IT IN SPACE. GLASS, METAL, CARBON AND CERAMIC MATRIC COMPOSITES ARE ALL POSSIBLE CANDIDATE MATERIALS BUT EACH SEEMS TO HAVE SOME LIMITATION. BY AN INNOVATIVE APPLICATION OF CHEMICAL VAPOR INFILLTRATION (CVI) ULTRAMET HAS DEMONSTRATED USING TUNGSTEN CARBIDE THAT A NEW CLASS OF CERAMIC MATERIALS CAN BE FABRICATED: CERAMIC HONEYCOMBS. IN PHASE I OF THIS PROGRAM ULTRAMET PROPOSES TO DEMONSTRATE THE FEASIBILITY OF FABRICATING STIFF, STRONG, LIGHTWEIGHT HONEYCOMB STRUCTURES OF BORON, BORON CARBIDE OR SILICON CARBIDE.