通过在我国江津典型工业污染大气环境进行大气暴晒实验,测定了1060纯铝、2A12铝合金和7A04铝合金在该地区的腐蚀速率,利用扫描电子显微镜(SEM)、能量色散X射线谱(EDX)、红外光谱(FT—IR)和X射线衍射仪(XRD)观察分析3种铝合金腐蚀表面形貌、元素分布和腐蚀产物结构。结果表明:随腐蚀时间的延长,铝及其合金腐蚀产物不断增多,失重数值增加,腐蚀失重与时间的关系呈幂函数规律(C—A t^n);腐蚀产物形貌呈块状或粒状,呈现不均匀的凹凸形貌;腐蚀产物主要为Al(OH)3和Al2(SO4)3·14H2O;耐蚀性能由强至弱依次为1060〉2A12〉7A04。
The corrosion behaviors of aluminum alloys 1060, 2A12, and 7A04 in Jiangjin atmospheric environment were investigated by the mass loss method. Scanning electron microscopy (SEM) was used to observe the surface morphology; energy dispersive X-ray detector (EDX) and X-ray (XRD) were employed to analyze the corrosion products. The results showed that corrosion product was increasing with testing hours prolonging, mass loss increasing. The relation of mass loss of corrosion product and time (h) accords with exponential attenuation rule as C = A t^n. Surface observation revealed that corrosion product was agglomerated and accidented. The main corrosion product is aluminum hydroxide and aluminum sulfate hydrate. Corrosion resistance of aluminum 1060 was the best, but that of aluminum alloy 7A04 was the worst.