稀土-铁系超磁致伸缩材料的耐腐蚀特性

The Corrosion Characteristics of Giant Magnetostrictive Materials Based REFe 2 System

本文用阳极极化法和扫描电镜等方法研究稀土－铁系超磁致伸缩材料的耐腐蚀性质，并用氧化增重法研究了这些材料的氧化行为。在室温碱性水溶液中这些合金具有抗弱碱性耐蚀性能，其耐腐蚀性随铁含量的增加而增大，添加Ａｌ或Ｃｒ不降低合金的耐蚀性，但添加Ｚｎ或Ｔｉ则会降低合金的耐蚀性。腐蚀机理是由于析出的富稀土相被优先溶解。热处理能略改善耐蚀性。Ｔｂ０．２７Ｄｙ０．７３Ｆｅ１．

The corrosion characteristics of the giant magnetostrictive materials have been investigated using the methods of potentiokinetic polarization and scanning electron microscopy etc, and their oxidation behaviors have been studied by oxidation gravimetical testing. The results show that these alloys are of weak corrosion resistance in the aqueous solution at room temperature. The corrosion resistace increases with increasing the content of Fe in Tb 0.27 Dy 0.73 Fe x alloys. The addition of Al or Cr does not decrease the corrosion resistance, but the addition of Zn or Ti decreases the corrosion resistance in Tb 0.27 Dy 0.73 Fe 1.8 M (M is Al, Cr, Zn or Ti)alloys. The corrosion mechanism of these alloys is the preferrential corrosion in the rare earth-rich phase. The corrosion resistance of these alloys is slightly improved after heat treatment. The oxidation temperature of these alloys is around 530℃ in atmosphere.