WC reinforced W Cu composites have excellent wear resistance and high-temperature strength , and can replace conventional W Cu composites in special applications. In this work, W Cu composites with WC@W core-shell structure are fabricated through a novel microwave-heating salt-bath carbonization (MSC) and infiltration method, using graphite as the carbon source. The MSC behavior of W particles and the influence of the graphite content on the microstructure and properties of the W Cu composites are investigated. The results show that WC is successfully coated on the surface of W particles by the MSC method. The addition of an appropriate amount of graphite to W powders can improve the high-temperature mechanical properties and wear resistance of the W Cu composites. Compared with conventional W Cu composites, the W Cu composites with 0.9 wt% graphite have higher thermal conductivity (245 W/(m·K)), higher hardness (293.8 HV), higher bending strength (1089.4 MPa), and higher compressive strength (410 MPa| 600 °C ). The addition of graphite also significantly improved the wear resistance of the W Cu composites. The average coefficient of friction (CoF) and wear rates (WR) of WCu9 composites are 0.51 and 5.37 × 10 −6 mm 3 N −1 m −1 , respectively. The WC reinforced W Cu composites prepared in this work provide an excellent approach to improve the wear resistance and high-temperature properties of guide plates in guide devices.
Benefiting from the extraordinary mechanical properties especially at elevated temperatures, Ni625/WC composites have been regarded as promising structural materials for deep well drilling. However, the addition and formation methods of WC would effect the mechanical properties of the composites greatly. In this work, Ni625/WC composites by spark plasma sintering technique are investigated, and the influences of WC by the external adding method and the internal in-situ formation method on the morphology, friction and fracture behaviors of the materials are analyzed systematically. It is found that the samples with externally added WC as the reinforcing phase possess enhanced wear resistance because of the high hardness and embedding depth of the externally added large-size WC. The large hardness difference with the matrix and the high brittleness lead to serious adhesive wear and poor toughness of the samples. On the contrary, the samples with in-situ WC as the reinforcing phase have superior toughness owing to the tighter bonding of in-situ generated WC to the matrix, lower brittleness of tungsten carbide and slower propagation of cracks. This work, with the systematic and comparative study of the incorporation of WC to the influence of mechanical properties of Ni625/WC, would enlighten the design of advanced metal-ceramic composites to meet the specific requirements of different structural materials.
危险品化学品经营许可证（带存储）