Preparing nano-structural WC-Co coatings by utilizing novel powder manufacturing route

Thermal sprayed cemented carbides such as WC-Co(Cr) and Cr3C2-NiCr coatings are well known and widely used for wear protection purposes. Submicron, nano-sized and multimodal carbides in cermets have shown promising results in retaining hardness and wear performance. In this study novel manufacturing route to produce nanostructural WC-Co powders and thermal sprayed coatings were utilized. This presented powder manufacturing method is based on use of water soluble raw materials as a starting media for synthesis to create in a single process a particle in where nano size carbides (50 nm) tightly bonded on metal matrix. Powders were manufactured via spray drying and heat treatment method from water based solution with raw materials ammonium meta tungstate (AMT) as a tungsten source, glycine as a carbon source and cobalt acetate as a cobalt source. Powder was heat treated in Ar atmosphere. Experimental powders were sprayed by HVAF-spraying. Morphology, microstructure and properties were analysed from the produced powders and HVAF-coatings.