Reaction behaviour, microstructure and mechanical properties of TiC-TiB2/Ni composite fabricated by pressure assisted self-propagating high-temperature synthesis in air and vacuum

The dense TiC-TiB2/Ni composite was successfully fabricated via a simple route where the pressure assisted self-propagating high-temperature synthesis (SHS) was directly ignited at 625 degrees C with the incorporation of air. The ignition temperature in air was much lower than that in vacuum (1040 degrees C). The composites made in air possessed the similar phase constituents and microstructure as well as comparable mechanical properties to those made in vacuum. The ignition temperature both in air and vacuum showed a significant dependence on Ni content and reactant particle size while the reaction products only showed a dependence on Ni content and B4C particle size, irrespective of Ti particle size. The density of the composite made in air and vacuum only depended on Ni content while the mechanical properties of the composites made in air and vacuum both showed a similar dependence on the Ni content and reactant particle size