Ultrafine Cemented Carbides with Cobalt and Iron Binders Prepared via Reactive In Situ Sintering

Abstract

Reactive sintering of cemented carbides involves mechanical and thermal activation of precursor elemental powders, followed by in-situ synthesis of tungsten carbide. This approach promotes formation of ultrafine microstructure favored in many cemented carbide applications. Our study focuses on the effect of mechanical activation (high-energy milling) on the properties of powder and following thermal activation (sintering) on the microstructure characteristics and phase composition. Reactive sintering proved effective – an ultrafine grained microstructure of cemented carbides with Co and Fe binders was achieved. Formation of tungsten carbide grains was complete at low temperature during reactive spark plasma sintering, resulting in textured microstructure with anisotropic grain formation and growth.