2D70铝合金管材硬质阳极氧化膜白色条状缺陷分析

Analysis on white stripe defect of hard anodic film on 2D70 aluminum alloy tube

针对某大规格2D70铝合金管材零件硬质阳极氧化后出现白色条状缺陷问题,通过成分分析,硬度和电导率检测,微观组织观察等手段对缺陷区域和正常区域进行了研究,发现缺陷区域的析出相较正常区域粗大是导致白色条状缺陷的根本原因,而这由固溶过程不恰当的吊挂方式引起。提出了新的吊挂方式,解决了上述问题。

Aiming at the white stripe defects appearing on 2D70 aluminum alloy tubes after hard anodization, the defect and normal positions were studied by composition analysis, hardness and conductivity testing, and microscopic structure observation. It was found that the basic reason for white stripe defect is that the precipitated phases at defect positions are coarser than those at normal positions, which is caused by inappropriate racking during the solution treatment. A new racking method was given, by which the white stripe defect problem is solved.