Effect of CaO doping on mechanical properties and thermal shock resistance of 10NiO-NiFe₂O₄ composite ceramics

Abstract

The CaO doped 10NiO-NiFe₂O₄ composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance of 10NiO-NiFe₂O₄ composite ceramics were studied. The results show that the samples mainly consist of NiO and NiFe₂O₄ when content of CaO is less than 4%(mass fraction), bending strength increases obviously by CaO doping. Bending strength of the samples doped with 2% CaO is above 185 MPa, but that of the samples without CaO is only 60 MPa. Fracture toughness is improved obviously by CaO doping, the samples doped with 2% CaO have the maximum fracture toughness of 2.12 MPa ·m^1/2, which is about two times of that of the undoped ceramics. CaO doping is bad to thermal shock resistance of 10NiO-NiFe₂O₄ composite ceramics.

Keywords

mechanical property / thermal shock resistance / CaO doping / 10NiO-NiFe₂O₄ / inert anode

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