含Fe和Mn的Ni_(30)Cu_(70)固溶体团簇模型与耐蚀性研究

提出了一个极限田溶体合金的团簇模型,在此基础上优化设计了添加Fe和Mn的Ni_(30)Cu_(70)(原子分数,%)固溶体合金成分.在该模型中,固溶的Fe和Mn以Ni为第一近邻形成12配位立方八面体原子团簇(Fe_(1-x)Mn_x)Ni_(12)而分散到Cu基体中,因此极限固溶体合金成分为[M_1/_(13)Ni_(12)/_(13)]30Cu_(70)=[(Fe_(1-x)Mn_xNi_(12)]Cua_(30.3),M=(Fe_(1-x)Mn_x).采用X射线衍射和电化学腐蚀测试等方法,研究了[(Fe_(1-x)Mn_x)Ni_(12)]Cu_(30.3)合金的微观组织与耐腐蚀性能的关系.实验结果表明,对应于极限同溶体状念的[(Fe_(0.75)Mn_(0.25))Ni_(12)]Cua_(30.3)合金,在3.5%NaCl溶液中具有相对好的耐腐蚀性能.

STUDY ON THE CLUSTER-BASED MODEL OF Ni_(30)Cu_(70) SOLID SOLUTION WITH Fe AND Mn AND ITS CORROSION RESISTANCE

Minor Fe and Mn additions are necessary to enhance the corrosion resistance of com-mercial Cu-Ni alloys. The present paper aims at optimizing the addition amounts of Fe and Mn in CuToNi30 (atomic fraction, %) alloy using a cluster based solid solution model. In this model it as-sumed that one Fe(Mn) atom and twelve Ni atoms formed a cluster consisted of Fe(Mn)-centered and Ni surrounded cube octahedron and the limit solid solution would be composed of isolated Fe(Mn)Ni_(12) clusters embedded in the Cu matrix. Thc ratio of the Fe(Mn) atoms and its surrounding Ni atoms is 1 : 12, and the limit solid solution composition of Fe(Mn) modified Ni_(70)Cu_(30) alloy is [M_1/_(13)Ni_(12/13)]_(30)Cu_(70)=[(Fe_(1-x)Mn_x)Ni_(12)]Cu_(30.3), M=(Fe_(1-x)Mn_x). The OM, XRD and electrochemical corrosion measurements were used to characterize the microstructure and corrosion resistance per-formance of [(Fe_(1-x)Mn_x)Ni_(12)]Cu_(30.3). The results indicated that the solid solubility limitative alloys [(Fe_(0.75)Mn_(0.25))Ni_(12)]Cu_(30.3) has the best corrosion resistance in 3.5%NaCl aqueous solution.