Processing and properties of bioinert ceramic materials in the system Al2O3-TiO2-SiO2

Very fine and sinterable ceramic powders (100-600 nm) in the system Al2O3-T iO2-SiO2 were obtained by the method of co-hydrolisis from organo-metallic precursors. Isostatically pressed powder compacts could be densified to a r elative high density (similar to 92 % th. density) at relative low temperat ures (1320-1380 degrees C). The technical coefficient of thermal expansion was measured by dilatometry. The value obtained (8.8 10(-6) 1/degrees C) co rresponds closely to that of Ti, opening the possibility to use Al2O3-TiO2- SiO2 ceramics to fabricate metal/ceramic composite implants. The measured m echanical properties of dense sintered Al2O3-TiO2-SiO2 material: Young's mo dulus, flexure strength and compression strength, are higher than those of pure TiO2. Highly porous Al2O3-TiO2-SiO2 ceramics (P similar to 65%) were o btained by the method of evaporation of hydrogen peroxide. These materials exhibited interconnected porosity and their properties, particularly the Yo ung's modulus, resulted very similar to those of bone, which is an importan t pre-requisite for the design of quirurgical implants.