Spark plasma sintering of WC-Co tool materials prepared with emphasis on WC core-Co shell structure development

Quasi-nano-sized WC core-Co shell structure composites were successfully fabricated by the wet chemical reduction method by introducing uniformly dispersed WC powders of 300-nm size into the Co(OH)2, which was subsequently reduced to Co shell structure by drop-wise titration of H3PO2. X-ray diffractometer (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) identified WC core-Co shell phases which were subsequently ball-milled, compacted and finally densified at 1400-1450 °C by spark plasma sintering. WC-Co sintered composites thus prepared were analyzed to examine densification, hardness and fracture behavior: reasonably adequate post-sintering properties are attributable to improved WC core-Co shell structure afforded by the optimized mechanical alloying and SPS sintering processes.