摘要
采用电化学测试技术和原子光谱、电子探针等分析技术,研究了Ga对Al-Zn-In合金牺牲阳极电化学性能的影响,分析了Ga、In等元素在合金中的分布形态和在铝合金活性溶解过程中的作用.结果表明,在3%的NaCl溶液中Al-4%Zn-0.022%In-0.015%Ga牺牲阳极工作电位为-1039mV,电流效率为96.3%.随着Al-Zn-In-Ga阳极中Ga的增加,阳极工作电位负移、电流效率下降,孔蚀愈加严重.电子探针分析发现,在Al-4%Zn-0.022%In-0.015%Ga阳极中Ga均匀地固溶于合金中,而In在阳极表面产生局部富集.Al-Zn-In-Ga阳极由于In3+的活化作用,破坏了表面钝化膜,使电极电位负移,从而激活了Ga3+的活性,使得Ga3+、In3+、Zn2+等产生共同沉积,维持了阳极活性溶解.
Effects of Ga on the electrochemical properties of Al-Zn-In sacrificial anodes in 3% NaCl solution were investigated by means of electrochemical techniques, atomic spectrum and electron-probe experiments. The distribution and the role of alloying elements such as Ga and In in the active-dissolving process of Al-Zn-In sacrificial anodes were analyzed. The results show that Al-4%Zn-0.022%In-0.015%Ga is a kind of ideal sacrificial anode with its operating potential of (-1 039) mV (SCE) and current efficiency of 96.3%. With the increasing of Ga amount while the other alloying elements are unchanged, potentials of aluminium-based alloys shift negatively but their current efficiency drops down and pitting corrosion increases evidently. Gallium distributes homogeneously in the alloy while indium gathers locally. Because of the activing effect of In^(3+), the surface passivated membrane is destroyed, potentials shift negatively, and with In^(3+) and Zn^(2+) together, Ga^(3+) promotes the aluminium alloy to dissolve actively.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2004年第4期502-505,共4页
Journal of Dalian University of Technology
