MOLYBDENUM DISILICIDE MATRIX COMPOSITES REINFORCED WITH MICROPARTICULATE TITANIUM CARBIDE

MOLYBDENUM DISILICIDE (MOSIE2) BASED INTERMETALLIC MATERIALS HAVE PROVEN TO BE RATHER FORMIDABLE MATERIALS TO PROCESS BECAUSE OF THEIR EXTREME BRITTLENESS AND POOR FRACTURE TOUGHNESS AT LOW TEMPERATURE. ANOTHER DRAWBACK OF THESE MATERIALS IS THEIR INSUFFICIENT CREEP STRENGTH AT HIGH TEMPERATURES. THE PROPOSED RESEARCH FOCUSES ON PREPARATION OF MOSIE2 BASE COMPOSITES REINFORCED WITH A HIGH VOLUME FRACTION OF ULTRAFINE PARTICLES OF HARD REFRACTORY TITANIUM CARBIDE UNIFORMLY DISPERSED THROUGHOUT THE MATRIX VIA A RAPID SOLIDIFICATION-MELT SPINNING TECHNIQUE. MOSIE2 ALLOY CONTAINING TIC WILL BE PREPARED AS RAPIDLY SOLIDIFIED (RS) POWDERS. RS POWDERS WILL BE COMPOSITED WITH A 3D-NETWORK OF NIOBIUM WIRE (15%). THE DUCTILE NB WIRE IS ANTICIPATED TO IMPROVE FRACTURE TOUGHNESS OF MOSIE2 MATRIX COMPOSITES BY THE CRACK BRIDGING AND CRACK BLUNTING MECHANISM. THE ULTRAFINE RIC DISPERSOIDS WILL LEAD TO IMPROVED CREEP STRENGTH BY OBSTRUCTING DISLOCATION MOTIONS, AND PINNING DISLOCATIONS/GRAIN BOUNDARIES. COMPOSITE MATERIALS WILL BE CHARACTERIZED FOR HIGH TEMPERATURE CREEP STRENGTH AND LOW TEMPERATURE FRACTURE TOUGHNESS PROPERTIES. MICROSTRUCTURE OF MOSIE2 MATRIX COMPOSITES WILL BE INVESTIGATED BY THE SEM AND TEM TECHNIQUES.