Fabrication and mechanical properties of ultrafine grained WC–10Co–0.45Cr3C2–0.25VC alloys

The ultrafine grained WC–10Co–0.45Cr3C2–0.25VC alloys were fabricated through planetary ball milling and low pressure sintering. The effects of the cobalt particle size, milling speed and sintering temperature on the microstructure, hardness and fracture toughness of the ultrafine grained alloys were investigated using optical microscopy, scanning electron microscopy and mechanical testing. The results showed that the mechanical properties of the low pressure-sintered alloys substantially depend on the milling speed and sintering temperature. At the same time, the hardness and fracture toughness of the samples can be increased from 1703 MPa and 8.90 MN m−3/2 to 1789 MPa and 11.21 MN m−3/2, respectively, when the cobalt particle size is reduced from 17 μm to 1.4 μm.

Research Highlights
► Ultrafine grained WC-Co alloys were fabricated using traditional techniques.
► Decreasing cobalt size can increase mechanical properties of the WC-Co alloys.
► Milling speed has important effects on the mechanical properties of the alloys.
► Sintering temperature also has obvious effects on the mechanical properties.