Densification and sintering dynamics of 10NiO-NiFe₂O₄ composites doped with CaO

Abstract

The effects of CaO content in the range from 0 to 4.0%, and sintering temperature on the phase composition, relative density and electrical conductivity of 10NiO-NiFe₂O₄ composites doped with CaO were studied. The results show that there is no change of structure for NiO or NiFe₂O₄; there is apparent oxygen absorbing and releasing behavior during the heating process in air for 10NiO-NiFe₂O₄ composites. Introduction of CaO can accelerate the densification of 10NiO-NiFe₂O₄ composites. The maximum value of relative density is 98.75% for composite doped with 2.0% CaO and sintered at 1 200 °C, which is beyond about 20% for the undoped composites. The sintering activated energy of sample containing 2% CaO decreases by 15.87 kJ/mol, compared with that of the undoped sample.

Keywords

aluminum electrolysis / inert anode / CaO doping / densification / sintering dynamics

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