Combined Synthesis of Heterogeneous Powders in CaB6–TiB2 System

Abstract

The heterogeneous CaB₆–TiB₂ powder mixtures were synthesized by reducing the mixture of TiO₂ and CaCO₃ with boron carbide in vacuum at 1400 – 1650°C. Reaction hot pressing was conducted according to the following regime: 1500°C (synthesis in vacuum) – 1900°C (pressing in Ar). As a result of synthesizing CaB₆–TiB₂ at mass ratio of 1:1 and 1600°C followed by isothermal soaking for 1 hour, a heterogeneous mixture was obtained containing crystalline phases of CaB₆ and TiB₂ with the residual B₄C impurity (0.5 wt. %). The powder particles represent grains measuring 1 – 3 μm in diameter and containing two phases CaB₆ and TiB₂ in the form of crystallites measuring 0.1 – 1.0 μm in diameter uniformly distributed throughout the particle volume.