Granulated WC-Co obtained by spray drying from aqueous suspensions

Abstract

Aqueous suspensions of hard metal powders and their use are known to have significant environmental and economic advantages over the systems employed nowadays using organic solvents. The present research describes developing a novel and less harmful processing route for hard metal production. Aqueous spray drying is convenient for obtaining dried WC-Co granules without extensive agglomeration. The spray-dried powders exhibit good flowability due to their shape and relatively narrow particle size distribution. The spray-dried granules have been pressed and sintered in an industrial sintering oven under a vacuum. The characterisation of the samples has highlighted the size, morphology, and some technological properties, while the sample's metallurgical properties have been assessed for the sintered compacts. By employing the abovementioned processes, both the granules and the subsequent hard metals revealed appropriate properties with biphasic (Co-WC) sintered compacts, which prove that such a process is feasible.