FLAME SYNTHESIS OF DIAMOND FILAMENTS FOR A COMPOSITE MATERIAL

COMPOSITES OFFER THE POTENTIAL FOR OBTAINING MATERIALS WITH SIGNIFICANTLY IMPROVED STRUCTURAL PROPERTIES (STIFFNESS, DAMAGE TOLERANCE, HIGH TEMPERATURE CAPABILITIES) COMPARED TO THAT OF ANY OF THE INDIVIDUAL COMPONENTS ALONE. DIAMOND WOULD BE A VERY INTERESTING COMPONENT IN A COMPOSITE MATERIAL BECAUSE OF ITS EXTRAORDINARY HARDNESS, HIGH ELASTIC MODULUS, LOW COMPRESSIBILITY, LOW THERMAL EXPANSION AND RESISTANCE TO CHEMICAL ATTACK. THIS PROPOSAL OFFERS THE DEVELOPMENT OF A PROCESS FOR GROWING DIAMOND FILAMENTS USING FLAME CHEMICAL VAPOR DEPOSITION (CVD). RESEARCH IN OUR LABORATORY DURING THE PAST YEAR HAS CONFIRMED HIGH GROWTH RATES OF DIAMONDS IN ACETYLENE FLAME AND, IN ADDITION, HAS SHOWN THAT UNDER CERTAIN CIRCUMSTANCES, DIAMOND FILAMENTS (APPROACHING SINGLE CRYSTALS)ARE FORMED. BY OPTIMIZING THE FLAME AND SUBSTRATE CONDITIONS IT SHOULD BE POSSIBLE TO GROW DIAMOND FILAMENTS IN A CONTINUOUS PROCESS. PHASE I RESEARCH WILL CONSTRUCT A NOVEL FLAME REACTOR TO ELUCIDATE THE GROWTH CHEMISTRY OF DIAMOND FILAMENTS BY FLAME CVD. IN-SITU DIAGNOSTICS WILL PROVIDE IMPORTANT INFORMATION ABOUT THE GROWTH ENVIRONMENT. USING THESE TWO ASPECTS, THE PHASE I RESEARCH WILL DEMONSTRATE THE DEPOSITION OF SHORT SINGLE CRYSTAL DIAMOND FILAMENTS. THE FILAMENTS WILL BE HIGH QUALITY (LOW GRAPHITE CONTENT AND GOOD UNIFORMITY) AND BE AT LEAST 1 MM LONG. PHASE II WILL SYSTEMATICALLY IMPROVE THE SIZE AND GROWTH RATE OF THE FILAMENTS UNTIL SINGLE CRYSTAL GROWTH OF DIAMOND FILAMENTS OF ARBITRARY LENGTH IS ACHIEVED.