Development and research of characteristics of two-layer diamond plates for drilling tools

Two-layer diamond-hard alloy plate is the cutting element of the drill bit and consists of a layer of polycrystalline diamond compact (PDC) binded with the superhard alloy substrate (WC-Co). In PDC cutter developed in FSBI TISNCM the plate of PDC, 2-3 mm thick and up to 18 mm in diameter, is bonded with a substrate of WC-Co, forming the working element of the drill bit. PDC consists of a diamond frame with grains of 20-10 microns impregnated with a binder metal Co. The ratio of the diamond fraction and the binder metal, as well as the size of the diamond grains vary, depending on the specifications. The entire PDC cutter is manufactured using high pressure and high temperature technology. The surface of the PDC plate is ground and polished to the required values. Full-scale tests of PDC cutters showed that their impact strength and wear resistance are determined by the quality of the contactlayer between the PDC and the substrate. The paper presents the results of the study of the mechanical characteristics of PDC cutters, as well as the microstructure, element and phase composition and defects of the contact layer of PDC with substrate.