NiFe₂O₄基金属陶瓷材料的制备及其耐腐蚀性能

来源期刊：中南大学学报(自然科学版)2004年第6期

论文作者：赖延清 秦庆伟 段华南 李劼 刘业翔

文章页码：885 - 890

关键词：铝电解;惰性阳极;腐蚀;金属陶瓷; NiFe₂O₄

Key words：aluminum electrolysis; inert anode; corrosion; cermet; NiFe₂O₄

摘    要：采用传统粉末冶金技术制备了铝电解用Cu- NiFe₂O₄和Ni- NiFe₂O₄金属陶瓷惰性阳极,并对其在Na₃AlF₆-Al₂O₃ 熔体中的腐蚀行为进行了研究。研究结果表明: NiFe₂O₄基金属陶瓷阳极的腐蚀行为与热力学计算结果吻合;金属Cu与NiFe₂O₄陶瓷的润湿性能不好,Cu- NiFe₂O₄金属陶瓷的致密化和导电性能难以提高;致密度过低时,会导致金属相高温氧化和电解质浸渗,电极肿胀、开裂;在电解过程中,5%Cu- NiFe₂O₄存在金属相聚集和在陶瓷基体中Fe优先溶解的现象,但金属铜并未发生阳极溶解;5%Ni- NiFe₂O₄金属陶瓷易实现致密化烧结,在电解过程中表现出良好的耐腐蚀性能,会发生金属Ni的阳极溶解,并存在陶瓷基体中铁优先溶解的现象。

Abstract: The cer met inert anodes with the compositions of Cu- NiFe₂O₄and Ni- NiFe₂O₄were developed by classical powder metallurgical technique respectively. The corrosion behaviors of NiFe₂O₄-based inert anodes in Na₃AlF₆-Al₂O₃ melts were investigated. The results show that the corrosion behavior of cermetmaterials is consistent with thermodynamic calculations. To improve densification and electrical conductivity are difficult be-cause copper has poor wetting characteristics to NiFe₂O₄ phase. The relative high porosity can lead to the oxidation of metals in Cu- NiFe₂O₄ cermets and electrolyte penetration into the anodes. The anode was badly swollen at the end of testing. The materials do not degrade during electrolysis via anodic dissolution of copper phase. Preliminary testing of 5%Ni- NiFe₂O₄cermetmaterials show that the anodes have excellent performance in cryolite-based melts. Nickel has the tendency to anodic dissolve and ferrite has the tendency of incongruent dissolution.