Studies On Structure And Properties Of Magnesium Oxide And Iron Oxide Doped Zirconia Solid Electrolyte

With its low price, reliable performance, steel became the essential part of materials for human life and production. Because of this, higher requirements with been proposed on the quality and performance of steel. For real-time monitoring of harmful impurities in the steel smelting process (such as oxygen, sulfur, phosphorus, etc.), used oxygen probe with zirconia solid electrolyte as the mainstay to measure the oxygen content and other impurities content in molten steel, which has made great achievements. However, as currently domestic large steel mills depend on imports of oxygen probe, a quick set of oxygen content has significant market and space for development.Dope zirconia solid electrolyte with moderate metal oxides (e.g. MgO, CaO, etc.)for a higher strength, thermal stability and ionic conductivity, and thus suitable for the modern steel-making process.In this paper, with magnesium oxide and iron oxide as stabilizer, magnesium stabilized, magnesium and iron stabilized zirconia solid electrolyte was prepared by solid state reaction. Samples were tested by XRD, SEM and AC impedance analysis for structural characterization and performance tests. The phase composition, microstructure and electrical properties of zirconia solid electrolyte influenced by adding magnesium oxide and iron-magnesium oxide were investigated.XRD results show that the sintering temperature, both mixed with magnesium oxide and iron-magnesium oxide co-doped can change the phase composition of the zirconia solid electrolyte. The influence of iron oxide on different Magnesium oxide content of zirconia solid electrolyte is varied. So in order to achieve the desired phase composition of the solid electrolyte, iron oxide content, magnesium oxide content and sintering temperature must be considered comprehensively.SEM results show that crystal structure of network appears in the solid electrolyte, and the formation are associated with sintering temperature, the mixing agent composition and content. Doped iron oxide can increase the density of the solid electrolyte. When mixing a certain component agent, increasing the sintering temperature can raise the grain size and density. Using AC impedance technique studied the electrical conductivity of series of samples with different components and different sintering temperature. Find that appropriate sintering temperature and adequate magnesium oxide and iron oxide content can increase the conductivity, and that there is no corresponding relationship between electrical conductivity and conductance activation energy. The introduction of iron oxide increases the conductivity activation energy of the solid electrolyte. With high temperature, magnesium -iron co-doped solid electrolyte will with great conductivity. After comprehensive considering the composition of solid electrolyte and the case of high temperature conductivity, choose 2.0% magnesium oxide and 0.5% iron oxide doped zirconia solid oxide electrolyte, with 1600℃as the sintering temperature.The phase composition of solidel ectrolyte directly affects electrolyte conductivity, while morphology can indirectly reflect its electrolyte conductivityOwn prepared quick set of oxygen sensor was performed field testing in Anshan Iron & Steel and West Iron. Found that own prepared quick set of oxygen sensor with high accuracy measurement, good reproducibility, high success rate, short response time. This achieves the comprehensive performance indicators of Heraeus products, which can be applied in practical production.