Pressureless Sintering of Boron Carbide-based Superhard Materials

摘要

Boron carbide-based materials B{sub}4C-Me{sub}xB{sub}y were densified by pressureless sintering in a vacuum furnace. Some transition metal carbides (TiC, ZrC, HfC, Cr{sub}3C{sub}2 and WC) from groups IV-VI were used as sintering aids. The optimal sintering temperature in the range 2220-2250°C was used for any composition. Here we show the possibilities to activate the mass transport of the B4C by the mechanism of liquid phase sintering. The method of reactive sintering of B{sub}4C in the presence of additives of some transition metal carbides allows in situ synthesis of dense B{sub}4C-Me{sub}xB{sub}y materials. Structural properties and fracture toughness of the B{sub}4C-based composite materials were discussed. The properties of some of these materials and the possibilities for their application are also discussed.