Effect of basalt fiber on the microstructure and holding strength of sintered WC-based diamond composite

Abstract

Basalt fiber (BF), a cheap and attractive fiber, was introduced into tungsten carbide (WC)-based diamond composite materials to study the effect of different mass fractions of BF on the structure and performance of WC-based diamond composite materials. The hardness, relative density and bending strength of the samples prepared by hot pressed sintering were tested, and the surface and fracture surface of the samples were analyzed by scanning electron microscope (SEM) and energy spectrometer (EDS). In addition, X-ray diffraction was used for phase analysis of the samples. The results show that adding proper amount of BF can improve the relative density, the bending strength and the holding force of the matrix material. Furthermore, the addition of proper amount of BF activates the sintering process which promotes the infiltration and diffusion of more binder elements on the diamond surface, improving the wettability of the matrix material to the diamond. When the mass fraction of BF is 1%, the composite material has the highest bending strength, and the holding force of the matrix to the diamond is found significantly improved. However, adding excessive BF is unfavorable to the mechanical properties of WC-based diamond composites. In summary, it is feasible and reasonable to add an appropriate amount of BF to replace part of the WC-based powder to prepare impregnated diamond drill bits.