Improvement of the Manufacturing Process of Tungsten Carbide-Cobalt Hard Metals by the Application of Sound Assisted Fluidization for the Mixing of the Powders

In this work, the technology of sound assisted fluidization has been used as an alternative mixing method to obtain homogeneous powder mixtures (WC, Co, and polyethylene glycol (PEG)) to be used in the standard steps of hard metal production. A preliminary experimental campaign was carried out to optimize the process parameters (sound intensity/ frequency and fluidization velocity) to perform the mixing process. After that, the obtained powder mixture was pressed and subjected to the sintering process. The quality of the final sintered products was assessed by using different techniques (SEM analysis, magnetic properties analysis, relative density, and Vickers hardness). The effects of two operating variables, mixing temperature and shaping pressure, were also studied aiming at improving the quality of the final products in terms of reduced porosity and enhanced density and hardness. Finally, also the effect of the addition of an inhibitor (Cr3C2) to the mixture was assessed.