6060铝合金表面氧化缺陷分析

Analysis of Defects of 6060 Aluminum Alloy after Surface Oxidation

针对6060铝合金表面氧化后的截面不同位置出现两种异色现象,利用扫描电镜和晶间腐蚀法对两种异色区域的显微组织、微区表面和耐蚀性能分别进行分析。结果表明:斑点区域第二相尺寸较正常区域小;斑点区域第二相主要由Al、Mg、Si、Fe等元素组成,而正常区域主要由Al、Mg、Si等元素组成,少部分含有Fe元素。斑点区域晶粒粒径较正常区域大,且晶间腐蚀也较严重。针对该现象,本文从熔铸和挤压工艺等方面分析其原因,并提出合理性预防建议。

The two kinds of coloring phenomena appear in different positions of the section of 6060 aluminium alloy after surface oxidation,the microstructure,micro-area surface and corrosion resistance of alloy are respectively analyzed using scanning electron microscopic and intergranular corrosion test in the areas of two coloring.The results show that the size of second phase in the spot area is smaller than that in the normal area.The second phase in the spot area includes mainly Al,Mg,Si and Fe,etc,but the second phase in the normal area includes mainly Al,Mg and Si,only a small number of regions contain Fe.The grain size of alloy in the spot area is larger than that of normal area,and the intergranular corrosion is more serious.In this paper,the reasons of coloring phenomena in different positions of the section of 6060 aluminium alloy are analyzed from the perspectives of casting and extrusion process,and then puts forward reasonable prerentive suggestion.