添加剂对金属陶瓷惰性阳极电解腐蚀的影响  

EFFECT OF ADDITIVES ON ELECTROLYSIS CORROSION OF CERMET INERT ANODE

作　　者：席锦会[1] 吉喆[1] 谢英杰[2] 顾永琴[1] 

机构地区：[1]中国矿业大学材料科学与工程学院,江苏徐州221008 [2]东北大学材料与冶金学院,沈阳110004

出　　处：《硅酸盐学报》2007年第11期1457-1461,共5页Journal of The Chinese Ceramic Society

基　　金：中国矿业大学科技基金(2006A050)资助项目。

摘　　要：采用粉末冶金法制备了无添加剂和添加V_2O_5的Ag-NiFe_2O_4/NiO金属陶瓷惰性阳极。铝电解试验在960℃进行,电流密度为0.5A/cm^2,电解时间为8 h,研究了无添加剂和添加2.0%(质量分数,下同)V_2O_5的Ag-NiFe_2O_4/NiO样品在Na_3AlF_6-5%CaF_2-5%Al_2O_3熔体中的腐蚀行为。研究表明:无添加剂的样品有较明显的腐蚀迹象,而添加2.0%V_2O_5的样品腐蚀后尺寸略有变化,表现出很好的耐腐蚀性。对腐蚀后样品的表面进行扫描电镜/能量色散X射线分析发现:在添加剂V_2O_5的作用下,Fe_2O_3在冰晶石中的溶解速率减小,从而抑制了陶瓷基体的溶解。另外,无添加剂样品表面各元素分布不均匀,说明无添加剂的样品在电解过程中发生选择性腐蚀,晶界等薄弱部位先被腐蚀。而添加了2.05V_2O_5的样品中各元素分布均匀,说明V_2O_5增强了晶界的稳定性,提高了材料抗电解质的腐蚀能力。Cermet inert anode materials of Ag-NiFeEO4/NiO with and without V2O5 added were prepared by the powder metallurgical method. The materials were applied to aluminum electrolysis testing in Na3A1F6-5%CaFE-5%Al2O3 for 8 h at 960 ℃ and the current density was 0.5 A/cm^2. It was found that the anode without V2O5 was corroded rather badly. However, the size of the anode with 2.0% （in mass） V205 changed only slightly, which shows that the anode has good corrosion resistance to molten cryolite-based melt. The surface of the inert anode was analyzed using scanning electron microscopy and energy dispersive X-ray analysis. The results indicate that V205 can control the dissolution rate of Fe2O3 and then control the dissolution of the ceramic matrix. On the other hand, the elements on the surface of the anode without V2O5 are distributed non-uniformly. Weak positions such as the grain boundary are corroded first. The elements on the surface of the anode with 2.0%V2O5 are distributed uniformly, which shows that V2O5 can strengthen the grain boundary, and thus improve the corrosion resistance of the material.

关 键 词：金属陶瓷 惰性阳极 五氧化二钒 铝电解 腐蚀速率 

分 类 号：TF777[冶金工程—钢铁冶金]