The sintering behavior in vacuum of ultrafine nonmilled titanium boride powder and a composite of the latter with CaB6 was investigated. It was shown that such titanium boride powders and TiB2−CaB6 composites poses better sinterability than conventional powders; the temperature of rapid densification was approximately 200°C lower. The introduction of ∼1% each of Fe and Ni into the TiB2−5% CaB6 composite noticeably accelerated densification due to the formation of a transient liquid phase. The effect was further enhanced by the activation of surface and volume diffusion by the solution of Fe and Ni in TiB2, as well as recrystallization processes.