Research and Analysis of the Causes of White Stripe Defects in the Anodizing Process of 1100 Aluminum Plates

In order to investigate the causes of white stripe defects on the surface of 1100 aluminum plates during the anodizing process，chemical composition analysis， macroscopic morphology analysis， surface roughness analysis， scanning electron microscopy (SEM)， energy dispersive spectroscopy (EDS) analysis and X-ray diffraction (XRD) analysis were conducted to study the white stripe defects on the surface of the anodized 1100 aluminum plates.Results showed that the types， quantities and area fractions of AlFeSi phases in the white stripe defect areas were fewer than those in the normal areas.After anodizing fewer pits and corrosion holes caused by the AlFeSi phases were found in the white stripe defect areas compared to the normal areas.The surface roughness was also smaller in the defect areas than in the normal areas，which led to less diffuse reflection under natural light in the white stripe defect areas than in the normal areas， making them appear brighter and whiter compared to the normal areas.