Structure and microhardness of binding for diamond tools based on tungsten carbide obtained by impregnation of iron-carbon melt

Abstract

In this work, an experimental modeling of the technology for producing a matrix by sintering a diamond-containing briquette with a filler of tungsten monocarbide powder impregnated with a Fe-C eutectic melt in a vacuum is carried out. The microstructure, elemental and phase compositions of the products formed in the process of sintering a diamond-containing matrix with impregnation with a Fe-C eutectic melt in vacuum have been studied by scanning electron microscopy, X-ray spectral and X-ray phase analyzes, and Raman spectroscopy. It was found that the matrix consists of 61.0% tungsten carbide phases, 17.0% of iron carbide, 16.5% of α-Fe, and 5.5% of graphite. The eutectic Fe-C alloy, which serves as a matrix binder, consists of a ferrite-pearlite metal base with graphite inclusions. It is shown that at the diamond - matrix interface, graphite inclusions are formed not as a continuous layer, but as discontinuous areas along the perimeter of diamond grains. The microhardness of the WC-based matrix impregnated with the Fe-C melt is ~ 11 GPa, which is more than 3 times higher than the microhardness of the WC-Co-Cu hard alloy matrix obtained by sintering with copper impregnation.The research results can be used in the development of technology for the manufacture of wear-resistant matrices of diamond tools of a wide class used in the processing of materials with a high level of hardness.