Enhancing the mechanical properties of coarse-grained cemented carbides by tailoring microstructure

Abstract

In this study, ultrafine WC@10Co powders were used for the fabrication of coarse-grained WC-10Co with almost full densification. The incorporation of WC@10Co resulted in a decreasing size of WC grain with a rounded shape, the mean free path of Co and the WC contiguity. Further, substantial Co with face-centered cubic structure dispersed uniformly in the cemented carbides with WC@10Co-contained intergranular fracture accompanied by a large number of plastic deformation tears of the Co phase at the fracture surface and crack bridges at the crack tip. Therefore, the hardness, fracture toughness and bending strength of cemented carbides with WC@10Co reached the highest levels of 1045.3 kgf m−2, 23.6 MPa·m1/2 and 2308 MPa, respectively. HIGHLIGHTS The ultrafine WC@10Co contracted size distribution of WC grain with a rounded shape. The uniformly dispersed Co with a high content of FCC structure was obtained. The as-obtained coarse-grained cemented carbides showed enhanced mechanical properties