【摘要】 采用电化学腐蚀和浸泡腐蚀研究了Al-7Si铸造合金在NaC1含量为3.5%的水溶液中的腐蚀行为,探讨了Mn、Sn对Al-7Si合金的塔菲尔曲线以及自腐蚀电位、腐蚀电流密度等电化学参数的影响,并利用电子分析天平和扫描电镜分别对各合金浸泡腐蚀后的质量损失和腐蚀形貌进行了测量与分析。结果表明,各试验合金均较快进入钝化状态。随着Mn、Sn的加入,各合金自腐蚀电位均向负向移动、腐蚀电流密度增高,腐蚀质量损失增大,耐腐蚀性能降低。同时合金的腐蚀形貌和腐蚀机理也发生转变。更多还原

【Abstract】 The corrosion behaviors of Al-7Si cast alloys in 3.5% NaCl aqueous solution were examined by using electrochemical corrosion and immersion corrosion tests.Influence of manganese(Mn)and tin(Sn)on the Tafel curves and electrochemical parameters,such as free corrosion potential and corrosion current densities,of Al-7Si alloys were investigated.Moreover,the weight loss and morphology of the alloys after immersion corrosion were measured and analyzed by analytical balance and scanning electron microscopy(SEM).The results indicate that all the tested alloys can be passivated rapidly,and their corrosion potential is drifted to negative,meanwhile,their corrosion current density and corrosion weight loss are increased with the addition of alloy elements Mn and Sn,greatly deteriorating the corrosion resistance of the alloy.In addition,the corrosion morphology and corrosion mechanism of Al-7Si cast alloys were described.更多还原