Metallothermic SHS of Ni–Cr–Ti–B composite materials from mixtures based on calcium chromates

The possibility of obtaining a composite material based on titanium and chromium borides with a nickel binder by metallothermic SHS was considered. In the experiments, calcium chromates CaCrO4 and CaCr2O7 were used as the chromium-containing component of green mixtures. Thermodynamic calculations showed that the combustion temperature of the mixture based on calcium dichromate (CaCr2O7) exceeded by 200°C the combustion temperature of the mixture based on calcium chromate (CaCrO4). The use of calcium dichromate allowed us to expand the limits of combustion and phase separation of the mixture, as well as to increase the yield of the target product. XRD analysis and SEM/EDS data showed that the obtained composite material contains triple boride Ni20AlB14 as a basis and chromium and titanium borides and titanium–chromium boride, which are uniformly distributed over the material.