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Synthesis of Composite Materials Based on Borides of Metals and Aluminum Oxide under the Combustion Conditions



Author(s)

R. G. Abdulkarimova¹, A. J. Seidualiyeva¹ and K. Kamunur²

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DOI:10.17265/2161-6221/2018.3-4.003

1. Al-Farabi Kazakh National University, Almaty 050040, Kazakhstan
2. Institute of Combustion Problems, Almaty 050012, Kazakhstan

The article presents experimental results on obtaining composites based on the systems TiB₂-Al₂O₃, CrB₂-Al₂O₃ and ZrB₂-Al₂O₃ by a method combining SHS (self-propagating high-temperature synthesis) and MA (mechanical activation). Using the thermodynamic calculation program “THERMO”, the adiabatic temperature and the composition of the equilibrium combustion products are calculated. It is shown that the products of exothermic interaction are refractory compounds of metal borides and alumina, which in the ceramic composite form a dispersed phase and a ceramic binder. The effect of duration of the activated mixing on the morphology of the reaction mixture and formation of the microstructure of the ceramic composite was studied. The realization of solid-state SHS is due to the formation of the initial powder mixture of ultradisperse reagent sizes during mechanochemical activation. The SHS products were examined by X-ray diffraction analysis and a scanning electron microscope. High-temperature phases of borides of chromium, titanium, zirconium, aluminum oxide and their spinel are found in SHS products. The purpose of this work is to investigate the influence of regimes for preparing reaction mixtures on formation of the microstructure of a ceramic SHS composite based on titanium, chromium and zirconium borides.

Composite materials, metal borides, SHS, MA.