镁合金等离子体微弧氧化过程负电压调控的研究

研究了AZ31镁合金在不同电压条件下的成膜效果,着重研究了在固定正电压而改变负电压的情况下的成膜厚度、致密度、耐腐蚀性能等差别,讨论了负电压在成膜过程中的作用,并且比较了在不同的溶液体系中负电压对于成膜性能以及二次放电现象的影响.结果表明：较低的负电压能在一定程度上促进氧化膜的生长,使致密的氧化层变厚,提高膜的性能.而高负电压会加速成膜速度并导致较为剧烈的二次放电现象,使膜的致密性降低,从而降低膜的性能.

Influence of negative potential on the growth of ceramic coatings on magnesium alloy in the process of plasma microarc oxidation

The oxide film on AZ31 magnesium alloy prapared by plasma microarc oxidation under different potential was investigated.The characteristics such as the thickness and corrosion resistance of the coatings were compared while the applied negative potential was changed.The effect of negative potential in different solutions and the second discharge phenomenon was emphatically discussed.It is found that the lower negative potential can favor the growth of oxide film with bether properties.The higher negative potential will increase the growth rate of film.However,an intensive second-discharge phenomenon is observed under high negative potential,which increases porosity of the film and leads to the decrease of the corrosion resistance.