锌对6063铝合金雪花状腐蚀的影响

来源期刊：中国有色金属学报1998年第2期

论文作者：余庆 吴继勋 卢燕平

文章页码：264 - 267

关键词：6063铝合金 局部腐蚀 阳极氧化 碱洗

Key words：6063 alloy , localized corrosion , anodizing , etching

摘    要：研究了合金中锌含量对6063铝合金型材在阳极氧化前表面预处理过程中发 生雪花状腐蚀的影响。结果表明，当合金中锌含量高于0.063%时，型材易发生雪花 状腐蚀，锌含量低于0.046%时， 型材一般不发生雪花状腐蚀。利用EPMA对表面进行成分分析发现，在碱洗过程中，锌含量较高的型材表面出现锌富集现象。这是因为合金中锌元素在碱洗过程中， 由于溶解与再沉积作用， 在型材表面富集，从而使合金表面电化学性质不均匀，造成碱洗不均匀， 引发雪花状腐蚀。

Abstract: One common corrosion is known as "galvanizing" in the pretreatment process of 6063 alloy for anodizing. The effects of zinc content in the alloy on "galvanizing" were studied. The results show that the "galvanizing" only appear on the 6063 alloy which contains zinc of more than 0.05%. EPMA analysis indicates that zinc segregates on the 6063 alloy with higher zinc content during etching in caustic soda solution. This phenomenon may result from the dissolution of zinc in the bath and then its reprecipitation on the surface of the alloy in the etching process.