Optimization of the obtaining temperature of powder composite material B4C – ZrB2 by the boron carbide method

Boron carbide is characterized by a unique combination of low density (2.52 g/cm3), high hardness (up to 40 GPa), chemical inertness, the high melting point (2450 °C); for these reasons, the ceramics based on this compound have found application in a number of areas of state-of-the-art technologies. However, it is difficult to obtain dense B4C-based ceramics because of a low value of the self-diffusion coefficient, low plastic deformation of this compound, and high sliding resistance between its grains. The use of modifying additives of transition metal diborides appears to be a promising approach to improving the operational characteristics of B4C-based ceramics. They tend to activate the sintering process by means of activation energy reduction, which leads to a decrease in a grain size, an increase in density, strength, and fracture strength of sintered compositions. Zirconium diboride is often used for this purpose. The objective of the work is to study the changes occurring in the charge of boron carbide, zirconium dioxide and carbon when it is heated to determine the temperature of the complete reagents transformation into B4C –ZrB2 composite mixture.