Mechanical properties and tribology of Si3N4-TiB2 ceramic composites produced by hot pressing and hot isostatic pressing

Ceramic matrix composites containing TiB2 as a particulate phase have been produced by hot pressing and hut isostatic pressing. The problems of the re activity of TiB2 with the Si3N4 matrix and with the sintering environment h ave been successfully addressed. A novel dual atmosphere sintering profile combined with low temperature hot pressing has been used to successfully pr oduce fully dense materials. The effect of TiB2 addition on mechanical prop erties has been investigated and the tribological behaviour of optimised co mpositions has been examined using a ball-on-disc apparatus. Wear coefficie nts and friction coefficients for Si3N4-Ti-2 composites have been measured and compared to monolithic Si3N4 materials. Composites containing TiB2 show significant improvements in hardness. fracture toughness and wear whilst a lso exhibiting electrical conductivity. (C) 2001 Elsevier Science Ltd. All rights reserved.