Influence of hardening additives on the characteristics of TiC‒Al2O3 ceramic composite tribological applications, obtained by SHS

In attempts to attain a SHS synthesized TiC‒Al2O3 composite with high density, homogenous microstructure and extra mechanical properties for using in aggressive media, addition of different reinforcements have to be studied and inspected. In this work, ductile nickel metal powder with different content (5‒20 wt. %) and 1 mole fraction dilution of alumina and zirconia with and without Ni addition are introduced to TiC‒Al2O3 ceramic and synthesized by combined self-propagating high temperature synthesis (SHS) and direct consolidation (DC) technique. The influence of nickel wt. % and dilution with zirconia and alumina on the phase composition, densification behavior, microstructure and mechanical properties of SHS synthesized TiC‒Al2O3 composite has been investigated and analyzed. Results revealed that, addition of 5 wt. % Ni gave the best densification behavior, microstructure and mechanical properties with exact formation of the target composite of TiC‒Al2O3. However, increasing Ni content higher than 5 wt % and dilution with zirconia and alumina led to disturbing the chemical reactions between the starting precursors, drooping and deterioration in density, microstructure and mechanical properties. Accordingly, this study suggests the addition of 5 wt. % Ni for a highly dense TiC‒Al2O3 composite with homogenized morphology and unparalleled mechanical properties. Moreover, the different investigated characteristics of the produced composites nominate it strongly to be used successfully in aggressive and tribological applications.