不同电解温度下 NiFe2 O4基金属陶瓷惰性阳极的熔盐腐蚀行为

Effects of temperature on the molten salt corrosion behavior of NiFe2 O4-based cermet

摘要:

采用等静压气氛烧结法制备 NiFe2 O4基金属陶瓷惰性阳极,在不同温度下进行电解试验,通过分析电解试样的表层形貌及组织成分,研究电解温度对 NiFe2 O4基金属陶瓷腐蚀的影响,并对其熔盐腐蚀行为进行探讨.研究结果表明：较高温度有利于电解稳定性的提高及表面致密保护层的形成,在925℃和960℃电解温度下阳极较为稳定,槽电压维持在3.0~4.0 V 之间；在880℃电解温度下阳极出现肿胀和开裂,槽电压异常升高,Al2 O3的溶解度较低,抑制了阳极与电解质熔体(尤其是 Al2 O3)的交互作用,降低了材料的耐蚀性能.

Abstract:

The NiFe2 O4 based cermets were prepared by isostatic pressing-atmosphere sintering method and their electrolysis corrosion in aluminum electrolysis at the different temperatures was examined. The surface morphology and chemical composition after electrolysis,the effect of electrolysis temperature of NiFe2 O4 based cermets was analyzed,and the molten salt corrosion behavior was also discussed. It was found that higher temperature is in favor of improving the stability of electrolysis and forming dense layer in surface. The stability of electrolysis was shown good performance and the Cell voltage is maintained between 3.0-4.0 V at the 925℃ and 960℃. The electrolysis anode was swelling and cracking,associated with the Cell voltage abnormal increase at the 880℃. The interaction of anode and electrolyte (especially Al2 O3 ) was suppressed due to the lower solubility of Al2 O3 (4.23 wt，)at lower temperature, deteriorating of corrosion resistance.