Growth Mechanism of TiB_2 Powder Prepared by SHS-metallurgy

TiB2 powder was prepared by SHS-metallurgy. The relative reaction systems were analyzed by DTA. The combustion products and leachable products were analyzed and characterized by XRD, SEM and granularity distribution. The results indicate that SHS reaction of Mg-TiO2-B2O3 system takes place through solid-liquid-liquid-solid reaction process. The combustion products consist of TiB2, MgO and a little Mg2TiO4 Mg3B2O6. The TiB2 particles become thinner when the sample pressure increases; TiB2 particle becomes thinner when adding MgO to the reaction system and TiB2 particles become bigger when adding TiB2 to the reaction system. The microstructure of combustion products and the forming mechanism of the different micro-regions were analyzed by Micro-region-technology based on SEM. The growth mechanism of TiB2 can be determined that one is growing in particle-particle interfaces and the other is growing within particles.