|Surface shading aluminum causes and Solutions|
The main reason analysis
Because the press outlet air amount is not enough,resulting in aluminum contact swing bed under higher temperature, cooling speed contact site different from other locations, a coarse Mg2Si phase precipitation, in the anodic oxidation treatment after the site into the dark grey.
1, strengthen the cooling intensity, avoid the swing bedprofiles of the interval is too small, ensure the temperature gradient cooling;
2, conditional factory should adopt methods of spraywater and air combined, can completely eliminate dark spots.