In order to solve the problem of color difference caused by sulfuric acid anodizing of the 7075 aluminum alloy thick plate,optical microscope,scanning electron microscope,room temperature tensile testing and other methods were used to study the microstructure and properties of different color parts.The results show that the cooling rate is the main reason for the color difference of the sulfuric acid anodized film layer of the 7075 aluminum alloy thick plate.In the parts that can not reach the required cooling rate during solution treatment,a large number of micron-sized η phases are generated,and the film layer is formed unevenly during the sulfuric acid anodizing,resulting in a gray-black appearance.In the parts that can reach the required cooling rate during solution treatment,the microstructure is dominated by nano-scale η'metastable precipitated phase,and the film layer is uniform during sulfuric acid anodizing,and the color is normally gray white.The gray-black part after sulfuric acid anodizing is re-heat-treated to regulate the microstructure,ant then the color of the film layer is returned to normal gray white.
7075 aluminum alloysulfuric acid anodizingsolution treatment and agingcolor difference
维普
万方数据
