More and more attention is being paid to the influence of powder mixing on the mechanical properties and corrosion resistance of WC-based cemented carbides. In this study, WC was mixed with Ni and Ni/Co, respectively, by chemical plating and co-precipitated-hydrogen reduction, which are labelled as WC-Ni^EP, WC-Ni/Co^EP, WC-Ni^CP and WC-Ni/Co^CP, respectively. After being densified in a vacuum, the density and grain size of CP were denser and finer than those of EP were. Simultaneously, the better mechanical properties of flexural strength (1110 MPa) and impact toughness (33 kJ/m²) were obtained by WC-Ni/Co^CP due to the uniform distribution of WC and binding phase and solid solution enhancement of the Ni-Co alloy. In addition, the lowest self-corrosion current density of 8.17 × 10⁻⁷ A·cm⁻², a self-corrosion potential of −0.25 V and the biggest corrosion resistance of 1.26 × 10⁵ Ω in 3.5 wt % NaCl solution were obtained by WC-Ni^EP because of the presence of the Ni-Co-P alloy.

The exploration of coarse-grained WC cemented carbide has become a research hotspot for its application in the fields of rock cutting and mining; a key issue is how to achieve uniform dispersion and densification of the sintered phase, as well as how to obtain better mechanical properties. In this paper, chemical co-precipitation, combined with hydrogen reduction, was adopted. CoCl₂·6H₂O and CeCl₃ were used as precursors to coat Co nanoparticles on the surface of WC powder while introducing different contents of cerium; the samples were then sintered and densified to obtain WC-Co(Ce) hard alloy materials. On the surface of the obtained WC particles, the distribution of Co(Ce) nanoparticles was uniform and dense, and the average particle size after sintering was 4.2 μm, which lies in the coarse-grained range. The addition of cerium elements significantly improves the flexural strength and impact toughness; when the cerium content was 0.5% and 0.6%, they increased to 2487 MPa and 36.1 kJ/m², respectively. The addition of Co(Ce) through the co-precipitation method could achieve a uniform coating of the Co phase, along with the uniform dispersion and densification of the sintered phase, giving the WC-Co(Ce) cemented carbide excellent properties.

The development of low-cost high-entropy alloys is promising to address the demands of expanding industrial applications. In the present research, Co-free FeNiCr medium-entropy alloys were prepared by arc melting and post-processing treatments. The influence of Fe content on the microstructure, mechanical properties and corrosion resistance of these alloys were clarified. The results show that the FeNiCr medium entropy alloys exhibit a single face-centered cubic structure. These alloys consist of a multitude of fine grains and a high density of annealing twining boundary distributed at the interface of the larger grains. The Fe40Ni30Cr30 exhibits both high strength and excellent elongation. The excellent mechanical properties of FeNiCr alloys are mainly attributed to the solid solution strengthening, grain boundary strengthening, twinning induced plasticity (TWIP) effect, dimples toughening, and micropores toughening. The increase in Fe content has been observed to impede the segregation of Cr, dislocation pinning, and the nucleation of grains at the grain boundaries, leading to an increase in elongation and a reduction in strength. In addition, the electrochemical experimental results show that a stable passivation film is formed on the surface of Fe40Ni30Cr30 alloy during the corrosion process, which reduces the corrosion rate and improves the corrosion resistance of the alloy.