Effect of BaO addition on relative density and electric conductivity of xNi/10NiO-NiFe₂O₄ cermets

Abstract

xNi/10NiO-NiFe₂O₄ (x=5, 10, 17) cermets and those doped with 1% BaO (mass fraction) were prepared by cold isostatic pressing at 200 MPa and sintering in nitrogen atmosphere at 1 473 K. The effects of BaO addition on relative density, microstructure and electric conductivity of cermets were investigated. The results show that relative densities of xNi/10NiO-NiFe₂O₄ cermets (x=5, 10, 17) doped with 1% BaO at 1 473 K in nitrogen atmosphere are increased by 0.49%, 1.45% and 2.99% compared with those of the undoped BaO cermets, respectively. Moreover, the electric conductivities (21.98, 28.37 and 50.10 S/cm) of xNi/10NiO-NiFe₂O₄ cermets (x=5, 10, 17) doped with 1% BaO at 1 233 K are improved compared with those (18.70, 22.79 and 39.58 S/cm) of xNi/10NiO-NiFe₂O₄ cermets (x=5, 10, 17), respectively. This indicates that perhaps the addition of BaO or formation of BaFe₂O₄ and Ba₂Fe₂O₅ has an active effect on electric conductivities of xNi/10NiO-NiFe₂O₄ (x=5, 10, 17) cermets.

Keywords

Ni/10NiO-NiFe₂O₄ cermets / BaO doping / inert anode / electric conductivity / densification

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