Densification of Ni-NiFe2O4 cermets for aluminum electrolysis
(School of Metallurgical Science and Engineering, Central South University,
Changsha 410083, China)
Changsha 410083, China)
Abstract: The density of cermet inert anodes in aluminum electrolysis is of great importance. Ni-NiFe2O4 cermets were studied with respect to their densification affected by ball milling time, particle size of raw powders, contents of metallic phase, sintering atmosphere and temperature. The results show that, prolonging ball milling time will increase the density with the optimum value of 150min; cermets containing 0-15%Ni(mass fraction) have high relative density ranging from 94% to 96%, but with Ni content increasing, the density slightly decreases; weak reductive atmosphere is favorable to densification; the relative density increases from 80.38% to 96.85% with the sintering temperature increasing from 1100℃ to 1300℃ while it decreases at 1400℃, which may be due to crystal grain coarsening. So the sintering temperature of Ni-NiFe2O4 cermets in current work should be controlled at 1300℃, where the relative density is 96.85%.
Key words: Ni-NiFe2O4 cermets; densification; inert anode; aluminum electrolysis