Acquisition And Research On Property Of Micro-arc Oxidation On The Surface Of Aluminum And Silicon Alloy

Cast aluminum alloys are extremely widely used: ZL101A is used for making the parts of airplane, the parts of equipments, the shells of water pump, carburetors, the cylinders of water-cooled engine etc, the defect is the work temperature below 200℃; ZL109 is used for making pistons, the defect is the work temperature below 250℃, so it is important for heat protecting to ZL109, there are many technics for this, but the effect is not excellent, micro-arc oxidation is one of the best methods to solve the difficult problem that ZL109 directly creates appropriate metallurgy-conjoint ceramic oxide-film.Micro-plasma is shortly named Micro-arc oxidation. It is developed from tradition anodic oxidation. By using this technique, a layer of ceramic film can be formed on the surface of some value metals, such as Ah Mg, Ti and their alloys. As a new technique in the field of surface technology, it aroused the interest of many investigator in the world wide.I have found two kinds of cast aluminum alloys that the thickness of oxide-film is 120μm and the micro-hardness is over 2000 by micro-oxidation through watching the spark form of different phases and different methods, such as different shape, the action of different composition and concentration of electrolyte, different pre-heating treatment and so on. It extremely improved the working condition and performance of two kinds of cast aluminum alloy. Using SEM and XRD, I have analyzed the micro-shape and fabric of ceramic oxide-film , and test the capability of anti-heat-impact, anti-corrosion, and anti-external strike of ceramic oxide-film.The paper probes into the spark form in micro-arc oxidation, research the correlation between spark form with electrolyte parameters and film's surface quality respectively. Spark form reflects the quality of the film's surface. We could adjust electronic parameters acting on spark form to control film quality.Through lots of experimentations, I have made a systematic study to the technology of surface micro-arc oxidation on the cast aluminum alloy, and found some law of technological parameters influencing on the growth of oxide-film.Finally, I 'd like to sum up my studying work, and discussed some problems, which need further study in the future.