不同电导率溶液中镁合金微弧氧化陶瓷层的生长规律及耐蚀性

Growth Rhythm and Corrosion Resistance of Ceramic Coatings Formed by Micro-arc Oxidation on Magnesium Alloys in Different Conductivity Solutions

利用扫描电镜(SEM)和盐雾腐蚀试验等手段,研究了镁合金在不同电导率溶液中微弧氧化处理生成陶瓷层的生长规律及耐蚀性。结果表明:随溶液电导率的增大,发生微弧氧化现象的起弧电压减小,微弧氧化陶瓷层厚度表现出近似线性增长,陶瓷层表面微孔数目逐渐减少,微孔孔径逐渐增大,陶瓷层内显微缺陷数量逐渐增多;陶瓷层的耐蚀性随电导率的增大表现出先增后减的变化趋势,在溶液电导率为4 (?·m)-1～6 (?·m)-1 时,陶瓷层的耐蚀性较好。

The growth rhythm and corrosion resistance of ceramic coatings formed by micro-arc oxidation on magnesium alloys in different conductivity solutions was studied by SEM and salt spray tests respectively. The results show that as the solution conductivity increases, the arc starting voltage falls down, the thickness of ceramic coating represents linear growth, and the number of micro pores on the coatings surface decreases obviously, while the micro pores size increases. Moreover, the number of micro flaw in the cross-section of the coatings increases gradually. With the increasing conductivity, the corrosion resistance of the coatings increases, and is improved best at the conductivity of 4(Omega m)(-1)-6(Omega m)(-1).