ZnBTA对铝合金在中性NaCl溶液中孔蚀的抑制作用

分别用失重法、电化学方法和表面分析等手段研究了 ZnBTA 对 6063铝合金在中性 NaCl 溶液中孔蚀的抑制作用。结果表明:在 pH 5—7,Cl~- 浓度为 0.5 mol·L~(-1),ZnBTA 用量大于 0.1m mol·L~(-1)条件下,样品浸泡 1 080 h,缓蚀效率达99％;ZnBTA 既可阻止孔蚀的诱发,又可抑制孔蚀的发展,对电极阴、阳极过程均有明显抑制作用,显示出混合抑制型缓蚀剂的特征。电子探针分析结果证明,ZnBTA 可以阻滞 Cl~-在铝合金表面的吸附聚集过程。通过量子化学计算,分析了ZnBTA 协同效应的可能机理。

ZnBTA Inhibition to Pitting Corrosion of Aluminium Alloy 6063 in Neutral NaCl Solution

Using ZnBTA to inhibit the pitting corrosion of aluminium alloy 6063 in neu-tral NaCl solution was studied by way of loss weighing, electrochemicalmethod and surface analysis.The results show that its inhibition efficiencycan be up to 99% if pH=5-7,concentration of Cl~-=0.5mol/L and that of ZnBTA>0.1mmol/L with samples immersed in after 1 080h.Not only to resist the ini-tialization of pitting corrosion, but ZnBTA can also inhibit its propagation,since it inhibits both anodic and cathodic processes remarkably.ZnBTA is thuscharacterized as a corrosion-inhibitor suited to either anodic or cathodic pro-cess.EPMA analysis shows that ZnBTA can also inhibit the absorption/aggre-gation process of Cl~- on the sample surface of Al alloy.The mechanism of sy-nergistic effect of ZnBTA is discussed according to the electricity distributionof benzotriazole as calculated by HMO method.