Mg-Cu-Gd系非晶合金的腐蚀行为研究

Corrosion Characteristics of Mg-Cu-Gd Amorphous Alloys

利用极化曲线法、电化学阻抗技术(EIS)和扫描电子显微镜研究了非晶合金Mg65-xCu24+xGd11(x=0,2,4,6,8)在0.01 mol/L,pH=12的NaCl溶液的腐蚀行为。结果表明,在开路电位下,随Cu含量的提高,腐蚀电位Ecorr向贵金属方向移动,腐蚀电流icorr减小,电化学反应电阻Rt增大,说明Cu含量提高有利于减慢界面反应,提高非晶合金的耐蚀性。SEM和EDS结果表明,增加Cu含量缩短了Mg元素的活性溶解时间,加速了钝化膜的形成,非晶合金在含Cl-碱性溶液中的活性也得到降低。

The corrosion behaviors of Mg65-xCu24＋xGd11（x=0,2,4,6,8） amorphous alloys in 0.01 mol/L NaCl solution with pH=12 are studied by potentialdynamic method,electrochemical impedance spectrum（EIS） and scanning electronic microscopy.It is found that with the increase of Cu content in the open circuit,Ecorr is ennobled,and the corrosion current icorr decreases,the equivalent polarization resistance Rt deduced from EIS increases.The result shows that the increase of the Cu content helps to slow down interface reactions and improve the corrosion resistances of amorphous alloys.SEM and EDS results show that the increase of Cu content results in the shortened active dissolution time of Mg and the rapid formation of passive film.Meanwhile,the activity of amorphous alloys in the alkaline solution with Clis also decreased with the increase of the Cu content.