Abstract:NiFe₂O₄ceramic and NiFe₂O₄based cermets, expected to be used as the inert anodes in aluminum electrolysis, were prepared and their electrical resistivities were measured at different temperatures. The effects of temperature and composition on their electrical resistivities were investigated. The results indicate that the electrical resistivities of NiFe₂O₄ based cermets mainly depend on temperature, resistivity of ceramic matrix, composition and dispersion of the metal phase among ceramic matrix. The electrical resistivity of NiFe2O4ceramic decreases from 10.094Ω·cm to 0.475Ω·cm with increasing temperature from 573 K to 1 233 K. The electrical resistivities of NiFe₂O₄based cermets are greatly lowered, but decrease with increasing the temperature with similar trend compared to that of NiFe₂O₄ceramic. The resistivities of NiFe₂O₄based cermets containing 5% Ni, 5% Cu and 5% Cu-Ni alloy are 0.046 8, 0.066 8 and 0.0532Ω·cm at 1 233 K, respectively, which are all acceptable as inert anode materials compared to that of the current carbon anode used for a luminum electrolysis.

Key words: NiFe₂O₄ cermet; electrical resistivity; inert anode; aluminum electrolysis