摘要
用Tafel曲线和电化学阻抗谱(EIS)研究7075铝合金在不同pH值(pH=3、5、7、9、11)的0.6 mol/L Na Cl溶液中的腐蚀行为.结果表明,溶液pH值在3~7时,腐蚀电位正移,pH值在7~11时,腐蚀电位负移,pH值为11时腐蚀电位最负.pH值在3~11时,腐蚀速度呈现先降低后增大的过程,pH值为11时腐蚀速度最大,达到2.122 2 mm/a.在强酸溶液中,电化学阻抗谱中出现明显的感抗弧,表明存在不均匀点蚀现象.pH值为7和9时,电化学阻抗谱中只出现1个容抗弧,表明铝合金腐蚀属于金属基体溶解过程.pH值为11时,阻抗谱中出现2个容抗弧,表明铝合金腐蚀伴随铝合金的自溶解行为.
Corrosion performance of 7075 aluminum alloy in 0.6 mol/L Na Cl solutions with different pH values were investigated by Tafel curve and electrochemical impedance spectroscopy（EIS）.The results reveal that corro-sion potential shifts positively with pH value from 3 to 7,corrosion potential moves negatively with pH value from 7 to 11. The corrosion rate increases initially,and then decreases gradually with variation of pH value from^3 to11.The corrosion rate is maximum when pH is 11, reaching 2.122 2 mm/a.The obvious inductance arc has arisen in strong acid solution, indicating discrete pitting corrosion.There is only one capacitive arc at pH 7and 9, illustrating the corrosion is the dissolution process of metal substrate, but two at pH 11, illustrating that the corrosion is along with self-dissolution.
出处
《有色金属科学与工程》
CAS
2017年第4期7-11,共5页
Nonferrous Metals Science and Engineering
基金
国家自然科学基金资助项目(51664022)
