Preparation And Growth Characteristics Of Titanium Micro-arc Oxidation Film

Because MAO is a complicated process, which is controlled by multifactor, different technical parameters, as-deposited MAO coatings show various properties. Moreover, the experimental and theoretical results are not systematic or complete. Therefore, further research work on preparation and characterization of MAO coatings on Ti alloy substrates, which are extensively used in many various fields, is needed.In this thesis, the oxide films on TA2 pure titanium are prepared by a novel MAO power supply with intelligent multifunction. The composition and structure of the coatings are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical microscopy. During the experiments, the effects of the relative parameters on the growing properties are studied. At the same time, the mechanism of film produced is proposed. The results are asfollows.This thesis consists of three parts. In the first part, oxide coatings on Tialloy (TA2) are fabricated under the condition of the constant voltage. During MAO process, the coatings properties such as the coatings thickness, growth rate, surface morphology and phase component etc against treatment time and voltage are studied respectively. The results show that: (1) the coating thickness increases gradually with the increased treatment time,while the growing rate increases quickly at first, and then decreases gradually. With the treatment time increasing, the roughness and micropore size of the coating surface increase gradually, and the pore number increases little by little. The coatings mainly consist of rutile phase and anatase phase. The content of rutile increses with the treatment time, while the content of anatase decreases. (2) With the increases voltage, the coating growing rate increases gradually at first, and then decreases.