Titanium Carbide Powder from Magnesiothermic Combustion of Leucoxene: Obtained Particulate Nickel-Coated for Use as MMCs Reinforcement

Abstract

Titanium carbide (TiC) powder was synthesized by the magnesiothermic combustion of the TiO₂-rich alteration product leucoxene and activated carbon (AC) in argon. Leucoxene and C were combined at a molar ratio of 1.0 : 1.5, and the effect of magnesium (Mg) fuel in the reaction system was studied at ratios of 1.0, 1.5, 2.0, 2.5, and 3.0. XRD analysis showed that the as-leached powder from a reactant mixture with a Mg molar ratio of 3.0 has fewer unwanted phases, and that leucoxene, C, Mg mixed at 1.0 : 1.5 : 3.0 produce TiC powder of a higher purity than the other reacted mixtures. The higher purity of the product was due to the more exothermic character of the combustion reaction, which had a higher enthalpy of reaction (ΔH) and adiabatic temperature (T_ad). SEM observation of the as-leached powder revealed agglomerated fine particles of sub-micrometer size. The TiC powder was successfully coated with nickel by an electroless plating process. SEM/EDX demonstrated that the Ni-coated TiC powder consists of Ni particles smaller than 500 nm, which are well distributed on TiC particles.