Microwave sintering of hardmetals

Application of microwave radiation as a heat source for sintering of hardmetal is described. Sintering of hardmetal with microwaves leads to a finer microstructure because of lower sintering temperatures and shorter processing times. A further variant is the microwave reaction sintering of a powder mixture of metallic tungsten, carbon and cobalt to obtain finer microstructures than by the conventional route. Moreover, this process offers a great potential for simplifying and shortening the process sequence in hardmetal production. The in situ formation of WC-platelets during microwave reaction sintering was observed.