TiB2-TiC-SiC composites prepared through high-gravity field activated SHS

Abstract

TiB2-TiC-SiC composites were prepared by high-gravity activated SHS using (Ti+B4C+Si) mixing powders. XRD, FESEM and FETEM results showed that the matrix of composites was mainly composed of TiB2, TiC and β-SiC. Uniformly-distributed TiB2 platelets formed the skeleton of composites, and irregular TiC and β-SiC solids were embedded between TiB2 matrix. It is supposed that TiB2 phases firstly precipitate prior to TiC from the molten reactive product in high-gravity field due to higher concentration of boron atom, and SiC solids solidify at final solidification stage and feed the TiB2 platelet skeleton, which effectively reduce the porosity and promote the relative density of composites.