Y2O3- and NbC-doped ultrafine WC–10Co alloys by low pressure sintering

The nanocomposite WC–10Co powders were prepared through planetary ball milling method. The effects of minor Y2O3 and NbC additions on structure, hardness and fracture toughness of ultrafine WC–10Co alloys were investigated using X-ray diffraction, optical microscope, scanning electron microscope and mechanical properties tests. The results show that minor NbC additions refine the WC grains and increase the hardness of the base alloys. The additions of Y2O3 decrease the volume fraction of Co3W3C phase in ultrafine WC–10Co alloys after low pressure sintering, and thus increase the fracture toughness of the base alloys from 6.2 MN m−3/2 to 9.8 MN m−3/2.