Reaction-assisted sintering and platelet growth by adiabatic heating in WC–Si cermets

Enhanced densification is observed between 1323 and 1573 K during the sintering of nanometric WC powders with Si addition. Microstructural observations and thermodynamics suggest that the exothermicity of a silicidation reaction that can lead to a temperature excess of nearly 500 K is probably the cause. At higher temperatures, the adiabatic heat of reaction prompts the recombination-climb of existing 1/6<1¯21¯3> partials from the prismatic to the basal planes, resulting in sudden platelet growth by 2-D nucleation on the {112¯0} planes.