SYNERGISTIC SYNTHESIS AND FORMING OF ADVANCED MOSI2/SIC COMPOSITES

SELF-PROPAGATING HIGH-TEMPERATURE SYNTHESIS (SHS) IS A NOVEL PROCESS FOR SYNTHESIZING INTERMETALLIC, MICRO AND NANOPHASE COMPOSITES. SHS POWDERS CAN BE CONSOLIDATED VIA PLASMA SPRAYING TO HIGH DENSITIES TO PRODUCE HIGH TEMPERATURE STRUCTURAL OR WEAR-RESISTANT MATERIALS. SIC REINFORCED MOSI2 INTERMETALLICS ARE OF PARTICULAR COMMERCIAL INTEREST. BRITTLE MOSI2 CAN BE TOUGHENED THROUGH INCORPORATION OF DISPERSED PHASES. UNIFORM, MICRO/NANO DISPERSIONS OF SIC, OTHER CARBIDES, NITRIDES, OR OXIDES, AND OTHER INTERMETALLIC/CERAMIC MATRICES CAN ALSO BE PRODUCED BY SHS. THERE IS A GROWING NEED FOR MATERIALS WHICH CAN EXTEND COMPONENT LIFETIMES AND IMPROVE RELIABILITY IN THE INCREASINGLY SEVERE HIGH TEMPERATURE ENVIRONMENTS OF HEAT ENGINES AND MATERIALS PROCESSING (E.G., BURNERS FOR GLASS PRODUCTION). THIS RESEARCH EVALUATES THE SYNERGISTIC SHS PRODUCTION AND PLASMA SPRAY CONSOLIDATION OF SIC REINFORCED MOSI2 COMPOSITES TO UNDERSTAND PROCESS-STRUCTURE RELATIONSHIPS. PROCESSING RELATIONSHIPS ORIGINATING FROM SHS AND PLASMA SPRAY FORMING ARE LINKED THROUGH MICROSTRUCTURES AND PHASE CONTENTS. RESEARCH ESTABLISHES SHS PROCESSING CONDITIONS WHICH PRODUCE POWDERS OPTIMIZED TO YIELD DENSE PLASMA SPRAY DEPOSITS. EVALUATIONS ALSO EXPLORE THE LIMITATIONS OF SHS ON A COMMERCIAL SCALE.