SiC晶须增强NiFe_2O_4基惰性阳极材料烧结工艺研究

Study on sintering technique of NiFe_2O_4/SiC_w used as matrix of inert anodes

为改善铝电解惰性阳极用NiFe2O4 尖晶石材料存在的不足,首次采用固态合成法制备了NiFe2O4/SiCw 复合材料。利用扫描电子显微镜观察显微组织,由X射线衍射分析物相,研究了烧结温度和保温时间对体积密度、气孔率和微观结构的影响,通过DTA分析证明了低于1200℃时NiFe2O4 与SiC的热力学相容性,试验结果表明,当烧结温度为1180℃时试样微观结构最为均匀致密,当烧结时间>6h时密度和气孔率的变化趋于稳定, NiFe2O4/SiCw 复合材料最佳的烧结工艺为1180℃×6h。

In order to improve deficiencies of NiFe2O4 spinel used as matrix of inert anode in aluminium electrolysis, NiFe2O4/SiCw were prepared by the solid state reaction for the first time. Microstructural changes were observed by scanning electronic microscope and phase was determined with X-ray detector. Effect of sintering temperature and times on density, porosity and microstructure were researched, and the reasons that caused the difference were discussed deeply. At the same time the thermodynamical compatibility of NiFe2O4 and SiC was proved under 1200°C by DTA. The results showed that the microstructure was more homogeneous when the sintering temperature reached 1180°C and the density attained their maximum about 6 h sintering. The appropriate sintering technique of NiFe2O4/SiCw composite materials selected 1180°C × 6 h.