Mechanical properties and microstructural characteristics of WC-bronze-based impregnated diamond composite reinforced by nano-NbC.

A WC-bronze-based matrix and an impregnated diamond composite (IDC) reinforced by nano-NbC were fabricated through powder metallurgy to improve the lifespan of drilling bits. The density, hardness, bending strength, and wear resistance of the matrix and IDC were studied. The microscopic features were examined by scanning electron microscopy and X-ray diffraction. The results showed that when the nano-NbC content was 5 wt%, the hardness and bending strength of matrix were 43 HRC and 1085 MPa, increased by 26% and 28%, respectively. The IDC exhibited higher bending strength and the highest wear resistance, and the grinding ratio was 1150, which was approximately 2.4 times higher than that of IDC without the addition of nano-NbC. The indoor drilling tests showed that the drilling bit life expectancy was 78 m, improved by 70%. The enhanced compactness characteristics, grain refinement, and dispersion strengthening were the main reasons behind the enhanced properties. [Display omitted] • Nano-NbC reinforced WC-bronze-based impregnated diamond composites were fabricated. • The composites reinforced by nano-NbC exhibited better mechanical properties. • The life expectancy of drilling bits improved obviously via nano-NbC addition. • The microstructures and phase composition of composites were analysed in detail. • The strengthening mechanisms of nano-NbC were clarified. [ABSTRACT FROM AUTHOR]