SINTERING OF HIGHLY DISPERSED TITANIUM DIBORIDE AND COMPOSITE TITANIUM DIBORIDE-CALCIUM HEXABORIDE POWDERS

The sintering behavior in vacuum of ultrafine nonmilled titanium borid e powder and a composite of the latter with CaB6 was investigated. It was shown that such titanium boride powders and TiB2-CaB6 composites p oses better sinterability than conventional powders; the temperature o f rapid densification was approximately 200 degrees C lower. The intro duction of similar to 1% each of Fe and Ni into the TiB2-5% CaB6 compo site noticeably accelerated densification due to the formation of a tr ansient liquid phase. The effect was further enhanced by the activatio n of surface and volume diffusion by the solution of Fe and Ni in TiB2 , as well as recrystallization processes.