FLUID BED SYNTHESIS OF WC/CO NANOCOMPOSITE POWDERS

A RADICALLY NEW APPROACH TO THE IN SITU SYNTHESIS OF THE CONSTITUENT PHASES OF A COMPOSITE STRUCTURE HAS ENABLED THE PRODUCTION OF A NEW WC/CO MATERIAL WITH AN ULTRAFINE MICROSTRUCTURE. SUCH "CHEMICAL SYNTHETIC" TECHNIQUES REPLACE THE MECHANICAL MIXING AND MILLING PROCESSES USED IN CONVENTIONAL POWDER METALLURGY WITH CHEMICAL REACTION PROCESSING. CHEMICAL REACTIONS BUILD UP THE NANO- OR MICROSTRUCTURE FROM THE ATOMIC SCALE. THE RESULT IS THE POTENTIAL OF PRODUCING NEW MATERIALS WITH IMPROVED PROPERTIES AT LOWER COSTS. THE FEASIBILITY OF CARRYING OUT THIS CHEMISTRY IN A REACTIVE FLUID BED WILL BE EXPLORED. PARTICULAR ATTENTION WILL BE GIVEN TO CHANGES IN THE DRAG COEFFICIENTS, DENSITIES AND CHARGE SUSCEPTIBILITIES OF THE BED PARTICLES AS THEY ARE CONVERTED FROM PRECURSOR POWDER TO NANOCOMPOSITEBIMETALLIC W/CO POWDER AND FINALLY TO NANOCOMPOSITE WC/CO PRODUCT. THE METALLURGICAL AND CHEMICAL QUALITY OF THE PRODUCT POWDER WILL BE CAREFULLY EVALUATED. SUCCESS IN USING FLUID BED TECHNOLOGY FOR THIS PURPOSE WOULD PROVIDE FOR RELATIVELY EASY PROCESS SCALE-UP AND ENHANCE THE ECONOMIC COMPETITIVENESS OF THE CHEMICAL SYNTHETIC APPROACH. IT WOULD ALSO FACILITATE THE MANUFACTURE OF LARGER QUANTITIES OF NANOCOMPOSITE POWDERS FOR USE IN ONGOING EXPERIMENTS WHICH ARE DEVELOPING THE BASIC SCIENCE OF NANO-COMPOSITIVE MATERIALS. APPLICATIONS FOR THIS NEW CLASS OF CERMET-MATERIALS INCLUDES HARD FACING FOR HIGH PERFORMANCE BEARINGS, CUTTING TOOLS, KNIFE EDGES AND ROCK BIT INSERTS.