Modified WC-Co materials produced by the Spark Plasma Sintering method

The paper presents the results of research on ceramic materials with a tungsten carbide matrix produced by the method of sintering with pulse current – Spark Plasma Sintering. The subject of the research was ceramics with a WC matrix designed for cutting tools or dies. The aim of the research was to develop material compositions and to use SPS method in the production process of a small batch of machine parts. The properties of the sinters obtained from commercial WC-Co and from newly-designed composite materials based on commercial mixtures modified with the addition of metallic (Fe/Ni/Co, Co), ceramic (SiC whiskers, Al2O3 fibres, TiB2, B4C, Ti3SiC2), and super-hard (cBN) phases, and graphene were investigated. For each material, the sintering parameters were optimized to obtain the required physical and mechanical properties (including apparent density, Young’s modulus, hardness, fracture toughness and abrasion resistance). The best properties were obtained for the G35N carbi- de material with the addition of Al2O3 fibres (4 wt%). Such an addition of Al2O3 fibres increased the hardness of G35N carbide from 1190 HV30 to 1510 HV30 while maintaining its fracture toughness at 16-17 MPa·m1/2. In the case of H10 carbide material, the use of the metallic phase Fe-Ni-Co as a modifier resulted in the increase in fracture toughness KIC from 9.7 MPa·m1/2 to 16.4 MPa·m1/2.