Novel WC-Co-Ti3SiC2 cemented carbide with ultrafine WC grains and improved mechanical properties

Abstract

New WC-Co-Ti3SiC2 cemented carbides with different fractions of Ti3SiC2 were prepared and characterised in this study. The composites were processed by hot isostatic pressing, and their microstructural characteristics and mechanical properties were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) energy-dispersive X-ray (EDX) and indentation methods. The addition of Ti3SiC2 resulted in refined WC grains in the composites with uniform and narrow size distribution in the composites. Refinement was achieved by the decomposition of Ti3SiC2. The optimal composition of WC-Co-Ti3SiC2 was established to be 3.0 wt% of Ti3SiC2 when the hardness and indentation fracture toughness exhibited excellent values of 2076 kgf/mm2 and 10.1 MPa m1/2, respectively. The strengthening and toughening of WC-Co-Ti3SiC2 were attributed to the refinement of WC grains and to the intrinsic layered structure of Ti3SiC2, respectively.