The Preparation And Applied Study Of Aluminium Anodic Oxide Films

In this dissertation, the preparation of aluminium anodic oxide films is studied mainly through method of constant voltage oxidation in sulfur acid. Composition and structure of AAO films are observed by SEM and XPS. The polarization curve of films are determined by methods of electrochemical dynamic potential in 0.1mol/L NaCl solution. Corrosion resistance and limited thickness of films are investigated in different oxidation voltage, electrolyte concentration, electrolyte temperature and oxidation time. The results indicate that limited thickness of films have something to do with oxidation voltage, electrolyte concentration and temperature. Films have tumbled in aluminium group close, and there are some lacunas on films. When thickness, voltage and electrolyte concentration are increased, corrosion resistance of films are improved. Corrosion resistance of films have relation to the temperature of preparation of films.Ni nanowire arrays are made by method of AC electrodepositing. Composition and structure of samples are determined by SEM, EPMA, TEM, and XRD. Through change of surface color of AAO films, it is find that the electrodepositing voltage, concentration of metal ions, temperature of bath, pH of bath and deposited time of AAO template have all some influence on the growing rate of nanowires. When electrodepositing voltage, concentration of metal ions and temperature of bath are increased, growing rate of nanowires is quickened. High voltage and concentration of metal ions can lead to failure of deposition of Ni nanowires in AAO template. More high or low temperature and pH of bath are disadvantageous to growing of nanowires. Deposited time and circumstance of AAO template have effect on AC electrodepositing of Ni.The relations are discussed between growth of Ni nanowires and resistance of EIS. Magnetic hysteresis loop of Ni nanaowire arrays is measured by VSM. The results indicate that the value of EIS of porous AAO films are reduced along with the growing of Ni nanowires, so the growing of nanowires can be investigated by EIS. Ni nanowires have been prepared. Diameter and length of nanowires are approximate 30nm and 2 μm, and the ratio value of length relativing to diameter is 67. The Ni nanowire arrays have magnetic anisotropy.The relations of voltage and current are researched by methods of AC and DC in the system of Al/AAO/electrolyte solution. AC electrodepositing mechanism is discussed. The I/U relation of positive direction of Al/Al₂O₃ interface is that the current are augmented with the form of index. Contrarily, change of current along with voltage is little. Al/Al₂O₃ interfacehave property of PN ties. Al is N port, and AI2O3 is P port. The results of AC investigation indicate that AI2O3 interface have obvious rectifying properties. Nanowires keep growing when electrodepositing time are prolonged. When A1(OH)3 colloid are full of the whole bore of AAO template, Nanowires stop growing.The bores of AAO template prepared by second anodization are more orderly to first.