Al_(1-x)Fe_x在3.5% NaCl溶液中腐蚀行为影响的研究

Corrosion behaviors of Al_(1-x)Fe_x in 3.5% NaCl solution

为了研究铁的含量对铝的耐腐蚀性能的影响,采用高频熔炼方法制备了Al1-x Fex(x=0.0,0.2,2.0at%)合金,采用X射线衍射、金相分析、电化学测试等对Al1-xFex合金的结构、电化学腐蚀特性、在3.5%NaCl溶液中浸泡与电化学腐蚀前后的表面形貌等进行了分析。结果表明:铝及Al-0.2Fe合金在3.5%NaCl溶液中,由于Cl-离子的存在发生点蚀破坏,并随腐蚀时间的延长沿晶界向周围扩展,最终发生全面腐蚀;Fe的引入能够改变合金的腐蚀溶解过程,铁含量较小时,钝化区减少,击穿电位降低,随着铁含量的增加,钝化过程不明显,腐蚀电流增大,整个阳极区极化曲线类似于金属的活性阳极溶解过程。

The effect of iron addition on corrosion-resistance of aluminum was investigated.Al1-xFex alloys（x=0.0,0.2,2.0 at%） were prepared by high-frequency melting.The structure of alloys,potentiodynamic linear polarization curve,the changes of the surface morphology after corrosion and electrochemical corrosion in 3.5% NaCl solution were investigated by X-ray diffraction,metallurgical microscope and electrochemical analysis.The results indicated that pitting corrosion occurred for aluminum and Al-0.2Fe alloy in 3.5% NaCl solution due to the presence of Cl-.The corrosion dissolution process was changed by addition of Fe in aluminum.