Self-propagating high temperature synthesis of TiB₂–MgAl₂O₄ composites

Metal borides are widely used as heat-insulating materials, however, the range of their application in high-temperature conditions with oxidative medium is significantly restricted. To improve the thermal stability of structural materials based on titanium boride, and to prevent the growth of TiB₂ crystals, additives based on alumina-magnesia spinel with chemical resistant and refractory properties have been used. The aim of this work is to study the structure of TiB₂ with alumina-magnesia spinel additives obtained by self-propagating high-temperature synthesis (SHS). TiB₂ structure with uniform fine-grained distribution was obtained in an MgAl₂O₄ matrix. The material composition was confirmed by X-ray diffraction analysis (DRON-3M, filtered Co kα-emission), FTIR spectroscopy (Thermo Electron Nicolet 5700, within the range of 1300–400 cm⁻¹), and scanning electron microscopy (Philips SEM 515). The obtained material represents a composite, where the particles of TiB₂ with a size of 5 µm are uniformly distributed in the alloy of alumina-magnesia spinel.