A TRANSFORMATION TOUGHENED ZR02 WHISKER REINFORCED ALUMINA COMPOSITE

THERE IS A GREAT DEMAND IN SPACE, DEFENSE AND COMMERCIAL APPLICATIONS FOR AN OXIDATION RESISTANT, LIGHTWEIGHT, HIGH MODULUS AND HIGH STRENGTH CERAMIC COMPOSITE WITH EXCEPTIONALLY HIGH STATIC AND DYNAMIC TOUGHNESS. PHASE TRANSFORMATION TOUGHENING SUCH AS WITH ZR02 AND ABSORPTION OF MICROCRACKING AT BOUNDARY SURFACES SUCH AS AT WHISKER-MATRIX INTERFACES ARE KNOWN TOUGHENING-STRENGTENING MECHANISMS. THE FULL POTENTIAL OF THESE TOUGHENING MECHANISMS HAVE NOT BEEN ACHIEVED BY THE TRADITIONAL ROUTE OF COMBINING POWDERS AND CONSOLIDATING. COMBINING SOL GEL TECHNOLOGY WITH THE ADDITION OF WHISKERS CAN RESULT IN A FINE GRAINED ALUMINA MATRIX COMPOSITE WITH WHISKERS AND FINEGRAINED ZR02 AT THE ALUMINA GRAIN BOUNDARIES TO PRODUCE A COMPOSITE WITH SUBSTANTIALLY IMPROVED TOUGHNESS AND STRENGTH, AND OXIDATION RESISTANCE TO ABOUT 1500 DEGREES C. THIS PROGRAM UTILIZES UNIQUE SOL GEL TECHNOLOGY AND A STATISTICAL DESIGNED EXPERIMENTAL PROGRAM TO PRODUCE AN ALUMINA MATRIX COMPOSITE STRENGHTENED AND TOUGHENED WITH ZR02 AND WHISKERS WHICH WILL HAVE DIVERSE USES IN SPACE AND DEFENSE MISSION APPLICATIONS AND COMMERCIALLY IN CUTTING TOOLS AND HEAT ENGINES.