NiFe_2O_4/Ag惰性阳极的熔盐腐蚀性能

MOLTEN SALT CORROSION PROPERTY OF NiFe_2O_4/Ag INERT ANODES

以Fe_2O_3,NiO和Ag粉为主要原料,采用固相烧结工艺制备了NiFe_2O_4/Ag惰性阳极。采用X射线衍射和扫描电子显微镜对材料的组成和微观结构进行了研究,并测量了样品抗热震性、抗折强度、在冰晶石熔盐中的静态热腐蚀以及电解腐蚀速率,对其腐蚀过程作了初步探讨。结果表明惰性阳极由NiO,NiFe_2O_4尖晶石和Ag三相组成。随着金属Ag含量的增多,惰性阳极样品在冰晶石熔盐中的静态热腐蚀速率增加,由于抗热震性和抗折强度有了大幅提高,电解腐蚀速率降低。静态热腐蚀和电解腐蚀呈现出物理化学溶解过程,而且由于金属银对晶界的强化作用,电解腐蚀由晶粒开始。

NiFe2O4/Ag inert anodes were prepared by the solid-state sintedng method with Fe2O3, NiO and Ag as the main materials. The NiFe2O4/Ag inert anodes were characterized by X-ray diffraction and scanning electron microscopy. The thermal shock resistance, flexural strength and static thermal corrosion rates and electrolytic corrosion rates in cryolite molten salt were measured and the corrosion process was studied. It was found that the inert anode consisted ofNiO, NiFe2O4 and Ag. With the increase of Ag content, the static thermal corrosion rates of the samples increased. Because the thermal shock resistance and flexural strength were improved, the electrolytic corrosion rates decreased. The static thermal corrosion and electrolysis corrosion are controlled by physical and chemical dissolutions. Because the metal Ag intensified the crystal boundary, the electrolysis corrosion processes begin at the crystal grain.