Study of characteristics and properties of spark plasma sintered WC with the use of alternative Fe-Ni-Nb binder as Co replacement

Most of all WC-based cemented carbides use cobalt as binder due to the excellent strength and ductility that this combination provides. Motivators to find alternative binders have been related to factors such as the shortage and price oscillations of the cobalt and toxicity of the WC-Co system. In this work, Fe-Ni-Nb was used as alternative binder for WC sintered via spark plasma sintering (SPS) technique. The composites were sintered at different sintering temperatures (1100 °C, 1200 °C and 1300 °C). In addition, WC-Co was sintered at 1200 °C via SPS for comparison purposes. X-ray diffraction and Scanning electron microscopy (SEM) were employed as characterization methods to investigate the crystalline phase's formation, sintering effectiveness, porosity and phase distribution. Mechanical properties such as Vickers hardness, fracture toughness, nanohardness, elastic modulus and thermal properties (thermal expansion coefficient) were evaluated. The results demonstrate Fe-Ni-Nb as a viable alternative binder to cobalt in hardmetal applications. [Display omitted] •WC hardmetal composites with Fe-Ni-Nb binder were successfully produced by spark plasma sintering method.•During sintering at lower temperature of the WC-Fe-Ni-Nb cemented carbide, Ƞ phase was formed.•At optimal sintering temperature, the highest hardness, KIC, nanohardness and elasticity modulus were achieved.•Thermal expansion coefficient measured between 250 and 800 °C are reported.•The mechanical and thermal properties are comparable to the WC-Co benchmark.