On the self-propagating high-temperature synthesis of tungsten boride containing composite powders from WO3–B2O3–Mg system

Abstract In this research, the self-propagating high-temperature synthesis characteristics of the 2WO 3 ‒(1 +  x )B 2 O 3 ‒(9 +  y )Mg system were studied using H 3 BO 3 as the boron oxide source. The addition of extra B 2 O 3 and Mg was considered as the main process parameter to obtain tungsten borides phases. XRD results showed that tungsten element was the only phase remained after leaching of the products obtained with the stoichiometric composition. The extra B 2 O 3 and Mg acted as the diluent agents and decreased the adiabatic temperature and the reaction velocity as well as the products’ particle size. Moreover, tungsten boride containing composite powders were obtained. However, the type of the tungsten boride in the composites was dependent on the diluent agent. Fourier transformed infrared spectroscopy analysis showed that nearly-pure composite powders were obtained after acid leaching. Finally, based on the XRD phase analysis and differential thermal analysis results, a mechanism was suggested for the formation of the SHS products in this system.