Plastic shaping of NiFe2O4-based cermets using granular feedstock: microstructure and mechanical properties

Carbon-free aluminum electrolysis is crucial for achieving the low-carbon development and carbon neutrality in the future aluminum industry. NiFe₂O₄-based cermet is the potential candidate of inert anode, benefiting from the satisfactory corrosion resistance and high-temperature conductivity. Herein, complex-shaped 25(Cu–20Ni)/(NiFe₂O₄–10NiO) cermets were fabricated via a plastic shaping method using the polyformaldehyde (POM)-based granular feedstock. The feedstock showed uniform microstructure with evenly dispersed powders wrapped in polymers, which exhibited shear-thinning behavior during molding. Roles of the feedstock with different powder loadings in the morphology and bending strength of the cermets were investigated. High-precision gear parts exhibited no deformation, a high relative density over 98%. Investigation of different powder loadings revealed that parts prepared with a 56 vol% loading demonstrate the excellent performance, and possessed an impressive flexural strength of 178.4 MPa. This achievement provided a foundation for the future utilization of complex-shaped inert anode material components in industrial applications.