PLASTIC BEHAVIOR AND PROPERTIES OF TITANIUM CARBIDE AND TITANIUM CARBONITRIDE MONOLITHIC AND COMPOSITE MATERIALS

THIS PROJECT'S OBJECTIVE IS TO ACHIEVE A FUNDAMENTAL UNDERSTANDING OF THE PLASTIC BEHAVIOR AND PROPERTY-MICROSTRUCTURE RELATIONSHIPS IN TITANIUM CARBIDE (TIC) AND TITANIUM CARBONITRIDE (TICN) MATERIAL SYSTEMS. THE PHASE I APPROACH SYNTHESIZES MONOLITHIC TIC AND TICN CERAMICS USING SELF-PROPAGATING HIGH TEMPERATURE SYNTHESIS (SHS) AND COMPOSITE TIC-METAL AND TICN-METAL MATERIALS USINGSHS AND LIQUID-METAL INFILTRATION (LMI) PROCESSES. THE NEW COMPOSITIONS ARE BEING DEVELOPED BASED ON CAPILLARITY THERMODYNAMIC (WETTING), EXOTHERMIC REACTION (SHS), AND DENSIFICATION KINETIC (LMI) STUDIES. MICROHARDNESS, MACROHARDNESS, AND FRACTURE TOUGHNESS PROPERTIES WILL BE MEASURED ON THE NEW COMPOSITIONS. MICROSTRUCTURAL EVALUATION WILL CONSIST OF METALLOGRAPHIC, X-RAY DIFFRACTION, AND ELECTRON MICROPROBE ANALYSES. PROPERTY-MICROSTRUCTURE CORRELATIONS WILL BE OBTAINED FROM THE EXPERIMENTAL DATA. THEESE RESULTS WILL PROVIDE THE BASIS FOR AN UNDERSTANDING OF HOW NONOXIDE MONOLITHIC AND COMPOSITE MATERIAL SYSTEMS BEHAVE PLASTICALLY.