Effect of metallic content on sintering behavior of NiFe2O4-based cermet inert anode for aluminum electrolysis

In order to overcome the high carbon consumption and serious environmental pollution as a result of adopting consumable carbon anode, NiFe2O4-based cermet inert anode for aluminum electrolysis was prepared by powder metallurgy method using 85Cu-15Ni binary alloy as metallic phase. The metallic phase content was varied from 0 to 20 (mass fraction, %) with 5% intervals. The effect of metallic phase content on sintering behavior and microstructure was investigated by a thermal dilatometer and field emission scanning electron microscopy. The results show that the maximum linear shrinkage and linear shrinkage rates enhance with the increase of the metallic phase content, while the temperature of maximum linear shrinkage rate shows the opposite changing law. The sintering activation energy of the initial stage lowers from 471.13 to 236.47 kJ center dot mol(-1) with the metallic additive range from 0 to 20%. The introduction of metallic phase could effectively enhance the grain boundary bonding strength and increase the grain size step by step.