摘要
利用扫描电镜(SEM)和盐雾腐蚀试验等手段,研究了镁合金微弧氧化陶瓷层不同生长阶段的形貌特征及耐蚀性.结果表明:整个过程可分为三个阶段,即阳极沉积阶段、微弧阶段和局部弧光阶段.阳极沉积阶段是在阳极表面发生团絮氧化膜沉积与扩展的过程;微弧阶段是前期缺陷减少与消失并形成均匀膜层的过程,陶瓷层表面微孔孔径较小,膜层均匀致密;局部弧光阶段形成的放电微孔孔径较大,陶瓷层比较疏松.陶瓷层的耐蚀性则表现出先增后减的变化趋势.在微弧氧化处理8min～12min时,陶瓷层的耐蚀性最好.通过控制陶瓷层不同生长时期的能量分配,尽量延长陶瓷层的均匀生长过程。
SEM and salt spray test were employed to characterize the surface morphology and corrosion resistance of ceramic coatings formed by micro arc oxidation on magnesium alloy.The results show that the coating grows in the following steps,i.e.,the stage of anodic deposition,micro arc oxidation and local arc light.In the first stage of anodic deposition,the flocculent oxidation film deposits and extends on the surface of MB8 magnesium alloy.The next stage of micro arc involves the decreasing and vanishing of flaw in the coatings,and the ceramic film formed is relatively uniform and dense,with very small micro pores.However,in the last stage of local arc light,the relative large holes appear on the surface of the coatings,therefore,the ceramic film becomes looser.With increasing treated time,the corrosion resistance of the coatings increases,and is best at the treated time of 8～12 minutes before it deteriorates.By controlling the energy allocation of the different time and extending the time of uniform growth,the uniform and compaction ceramic coatings can be obtained.
出处
《中国腐蚀与防护学报》
CAS
CSCD
北大核心
2005年第2期97-101,共5页
Journal of Chinese Society For Corrosion and Protection
基金
国家"十.五"科技攻关计划 (2001BA311A6-3 )
关键词
镁合金
微弧氧化
陶瓷层
耐蚀性
magnesium alloy,micro arc oxidation,ceramic coating,corrosion resistance
