| Summary: | 碩士 === 大同大學 === 材料工程學系(所) === 100 === In this research the corrosion resistance and the surface flattening of a bipolar pulsed Micro-arc Oxidation (MAO) treatmented LAZ951 Mg alloy (Mg-9Li-5Al-1Zn) were studied. The main process variables include processing time from 5 to 20 min, reverse loading current (-I) from 1 to 3 Amp/dm2 and reverse loading time (Ton-) from 1,000 to 3,500 μs. Poperties of the resulted MAO film were examined by using SEM, EDS, XRD, ICP-OES, coating thickness gauge, surface topology interferometer and potentionstate. The results show that, when operated under a specific condition of processing time of 10 min, reverse loading current of 1 Amp/dm2 and reverse loading time of 3,000 μs, a MAO film with most satisfactory combination of corrosion resistance (Ecorr = -1.3 V, Icorr = 1.8×10－8 amp/cm2) and surface flatness (Rz = 7.6 μm) was produced. In the post-MAO treatment, it was found that a water soluble coating with 2% silane can effectively enhance both the corrosion resistance (Ecorr = -1.42 , Icorr = 3.5×10－9 amp/cm2) and surface flatness (Rz = 3.4 μm) of the MAO specimen.
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