On the mechanism of WC coarsening in WC-Co hardmetals with various carbon contents

Thus the mechanism of suppression of WC coarsening in WC-Co hardmetals with medium carbon contents when decreasing the carbon content is thought to be related to the carbon dissolution in the liquid binder. The limiting stage of WC coarsening in hardmetals with very low carbon contents corresponding to the formation of η-phase can be the carbon self-diffusion in WC grains towards the interface WC-liquid Co. It cannot be excluded also that the limiting stage of WC coarsening in this case might be related to the processes of W and C re-precipitation onto WC grains from the extremely W-rich and C-poor binder.