The Study Of Technology On Cast Aluminum Alloy Micro Arc Oxidation Coatingand And Its Wear Resistance

With the development of modern industry and technology, Aluminum alloy is widely used more and more,but they have poor wear-resistance,erosion-resistance and corrosion resistance,which greatly limit them apply fields.This problem need a kind of surface treatment technology to solve. Microarc oxidation technology is developed based on the technology of anodic oxidation,which is a new technique of ceramic oxidation film growth on the surface of Al, Mg, Ti and their alloys.Now the research on microarc oxidation of aluminum alloy is mostly focused on duralium alloy series, and that on cast aluminum alloy with high silicon content, which inhibition of microarc oxidation, is relatively less.Therefore, this paper systematically studied main influencing factors and properties of the oxidation film in the cast aluminum alloy microarc oxidation process,uesd asymmetric bipolar alternating pulse power supply, and study the effect of oxidation time, electrolyte concentration, power parameters, with the hardness,thickness, dense layer, dense layer ratio of the film as the main index, understand the basic rules of the cast aluminium microarc oxidation. Firstly,the microarc oxidation technology were introduced, and the development of the microarc oxidation technology at home and abroad are reviewed.Secondly, the growth mechanism of microarc oxidation films were analyzed, elaborated the classification of plasma, and theory was propoed that microarc oxidation process is firstly oxygen bubble hole bottom field of ceramic membrane breakdowntriggered the avalanche breakdown.Thirdly,with the ZL101 as material,a serial tests were taken in alkaline electrolyte. Which were studied the thickness of film, the hardness and ratio of dense layer in the different oxidation time, electrolyte parameters and electrical parameters, with detection instruction such as etm, xrd,sem etc., and achived the effects of process parameters and electrical parameters on oxidation film.Lastly, friction experiments were set up to study the wear extent and friction factor in different friction time.The comparative friction experiments with microarc oxidation, hard chromium plating and thermal spraying three kinds of metal modified techonology,and the friction experiments of the friction coefficient changes with the load were taken,to study the relationship between some process parameter and friction wear characteristics.The results show that, microarc oxidation film preparation parameters directly affect the properties of oxidation film, the control and optimization of process parameters, can predict, control and optimization of growth process of microarc oxidation film, and preparation of microarc oxidation film with good wear properties.