Study On The Influence Of Rolling Process On The Microstructure And Properties And Surface Topography Of High Voltage Anode Aluminum Foil

As the key material of alumilum electrolytic capacitors, the high voltage anode aluminum foil has strict requirements on microstructure and properties as well as surface quality. How to guarantee the microstructure and properties as well as surface quality of the high voltage anode aluminum foil in the rolling improvements is still a difficult technical problem. The influence of friction coefficients, rolling geometric conditions and speeds on the microstructure and properties as well as surface topography were studied in this paper based on the rolling experiments, in ord to provide guidance for the industrial high-efficient rolling of the high voltage anode aluminum foil.The main works and conclusions in this paper are as follows:(ⅰ) The rolling experiments with different rolling lubricants which had different mass fractions of additive were carried out to research the influence of friction coefficients on the deformation textures and recrystallization textures of the high voltage anode aluminum foil. The results show that neither too large nor too small friction coefficient were beneficial to the formation of copper texture and cube texture. When the mass fraction of additive in the rolling lubricant was5%, both the copper texture and cube texture had the largest orientation densities.(ⅱ) The rolling experiments with different rolling schedules were carried out to research the influence of rolling geometric conditions on the deformation textures and recrystallization textures of the high voltage anode aluminum foil. The results show that neither too large nor too small but suitable pass reduction was beneficial to the formation of copper texture and S texture. The large the pass reduction, the severe the inhomogeneity deformation, and the higher the orientation density of shear texture, then the lower the orientation density of cube texture.(ⅲ) The influence of intermediate rolling speeds on the deformation textures and recrystallization textures of the high voltage anode aluminum foil were studied. The results show that when the intermediate rolling speed were improved from lOm/s to12m/s, there were no significant changes for the orientation densities of the deformation textures, but the orientation density of cube texture increased slightly.(iv) The influence of finishing rolling speeds on the microstructure and properties of the high voltage anode aluminum foil were studied based on the industrial rolling experiments. The results suggest that when the finishing rolling speed was improved from5m/s to6m/s, the orientation densities of S texture and cube texture incrased, and the grain size decreased; But when the finishing rolling speed was improved to7m/s, the grain size incrased, and the orientation densities of B texture incrased while the S texture and cube texture decreased.(v) The influence of finishing rolling speeds on the surface topography of the high voltage anode aluminum foil was studied by the analysis of the lubrication regime, autocovariance function and power spectral density. The results show that when the rolling speed was increased from5m/s to7m/s, there was no obvious change for the transverse direction surface roughness of aluminum foil, but the rolling direction surface roughness decreased, and the surface topography of aluminum foil was improved.(vi) The influence of rolling speeds on the specific capacitance of the high voltage anode aluminum foil was studied. The results show that when the rolling speed increased, the etch pit number and pit size and pit depth on the foil surface were all increased, meanwhile, the pit fusion decreased, these factors led to the specific capacitance of the high voltage anode aluminum foil increased.