Study On Surface Antireflection Technology Of Aluminum Alloy By Electrochemical Corrosion Method

Anodic Aluminum Oxide(AAO)is a growth template currently recommended for the preparation of nanomaterials,the pores in the structure have a large aspect ratio,which are parallel to each other and arranged periodically,and the dense and ordered porous anodic aluminum oxide film can adjust the diameter and density of the pores by appropriately changing the electrochemical corrosion conditions within a certain range,these characteristics are widely used in the synthesis and assembly of different nano-structured materials.At the same time,the low dielectric constant of porous anodic alumina itself,coupled with the effect of air filling in the pores,can cause the change of effective refractive index,thereby affecting the optical reflection properties of the aluminum surface.This special structure also enables AAO materials to show potential application prospects in the fields of spectrum and solar energy applications,which has become one of the hot spots in current technology research.In this paper,the AAO material was prepared by electrochemical corrosion method for1060 aluminum,the AAO film was characterized by X-ray diffractometer,scanning electron microscope,energy spectrometer and UV-Vis-NIR spectrophotometer.The influence of various factors on the structure of the preparation process was studied,and the spectral test and analysis of the reflection performance were carried out,in order to provide reference for the wide application of AAO film in nanomaterial synthesis and optics.The specific work content and research results are as follows:1.The effects of high temperature annealing and electrochemical polishing on the surface morphology and microstructure of aluminum sheets in the pretreatment process were investigated,and the effects of different pretreatment processes on AAO film formation were analyzed.The optimal pretreatment process in this experimental sample was obtained by adjusting the combination of pretreatment parameters.The results show that the alloyingelements on the surface of the original aluminum material are easy to exist in the form of segregation,the high temperature annealing can make the surface grain grow.After electrochemical polishing,smooth aluminum sheets with uniform structure and composition can be obtained.The average reflectance of the aluminum sheet in the ultraviolet-visible region to the near-infrared region is above 90%.In the subsequent electrochemical corrosion process,compared with the original aluminum sheet,the porous anodic aluminum oxide film grown by the above treated aluminum sheet is flatter than the porous anodic aluminum oxide film grown from the original aluminum sheet,therefore,pretreatment can improve the quality of AAO film formation.2.This paper expounds the basic principle of AAO film formation,systematically studied the relationship between electrochemical corrosion process conditions and oxide film quality,and determined the primary and secondary factors which are most sensitive to the quality of the oxide film.The results show that porous alumina surface with 30nm--50 nm ? porosity above 60% mesoporous range and 130nm-150nm?porosity above 80% large pore size ordered densely packed were prepared by using sulfuric acid electrolyte system and oxalic acid electrolyte system respectively.The anode voltage and oxidation time are the main factors affecting the porous structure.Properly increasing the anode voltage contributes to the opening and growing orderly of the pores,andthe control of the oxidation time is mainly reflected in the shape and size of the pores.Electrochemical corrosion of aluminum at a specific anode voltage for an appropriate period of time,the hexagonal densely arranged self-organized growth will occur,and hexagonal cells composed of cylindrical nanopores and surrounding oxidized regions form a honeycomb structure,which greatly improves the order of AAO film.3.The surfaces of AAO with different pore sizes prepared by sulfuric acid and oxalic acid were continuously tested by using agilent carry-5000 UV-Vis-NIR spectrophotometer,and the effect of pore size on optical absorption performance was analyed.The results show that the optical reflectance of porous microstructure surface prepared by the same system has a certain correlation with the pore size,and the larger the pore size is,the lower the reflectance will be.While The surface of the two types of porous microstructures prepared under different systems has different reflection performances for different wavelengths of light waves,which is mainly reflected in the fact that the surface reflectance of the macroporous microstructure in1200nm-2500 nm the NiR region is higher than that on the mesoporous microstructure,and the surface reflectance of the macroporous microstructure in 200nm-800 nm the UV-Vis region is lower than that on the mesoporous microstructure.