Effects of sodium tungstate on properties of micro-arc coatings on magnesium alloys

来源期刊：中国有色金属学报(英文版)2010年增刊第2期

论文作者：赵芳 廖爱娣 张荣发 张淑芳 王海霞 史兴梅 李明杰 何向明

文章页码：683 - 687

Key words：magnesium alloy; micro-arc oxidation; electrolyte; sodium tungstate

Abstract: Anodic coatings were prepared by micro-arc oxidation on AZ91HP magnesium alloys in a base solution containing 10 g/L NaOH and 12 g/L phytic acid with addition of 0-8 g/L sodium tungstate. The effects of sodium tungstate on the coating thickness, mass gain, surface morphology and corrosion resistance were studied by eddy current instrument, electronic scales, scanning electron microscope and immersion tester. With the addition of sodium tungstate, the electrolytic conductivity increases and the final voltage decreases. The sodium tungstate has a minor effect on the coating thickness, but lightens the coating color. With increasing sodium tungstate concentration, the size of micropores on the coatings is enlarged and the corrosion resistance of the anodized samples decreases.