The Structure and Microhardness of Binding for Diamond Tools Based on Tungsten Carbide Obtained by Impregnation with an Iron-Carbon Melt

摘要

Experimental modeling of the technology for producing a matrix by sintering a diamond-containing briquette with a filler consisting of tungsten monocarbide powder impregnated with a Fe-C eutectic melt in vacuum is performed in this work. The microstructure and elemental and phase compositions of the products formed in the process of sintering of the diamond-containing matrix with impregnation with a Fe-C eutectic melt in vacuum are studied by scanning electron microscopy, X-ray microanalysis, X-ray phase analysis, and Raman spectroscopy. It is found that the matrix consists of 61.0% tungsten carbide, 17.0% iron carbide, 16.5% alpha-Fe, and 5.5% graphite phases. The Fe-C alloy eutectic that acts as a matrix binder consists of a ferrite-pearlite metal base with inclusions of graphite. It is shown that, at the diamond-matrix interface, the graphite inclusions are formed not as a continuous layer but as discontinuous areas along the perimeter of the diamond grains. The microhardness of the WC-based matrix with impregnation with a Fe-C melt is similar to 11 GPa, which by more than three exceeds the microhardness of a WC-Co-Cu hard-alloy matrix obtained by sintering with impregnation with copper. The obtained results can be used in the development of production technology of wear-resistant matrices for a wide variety of diamond tools used in the processing of materials with a high level of hardness.