镁合金微弧氧化陶瓷层生长过程及微观结构的研究

利用扫描电镜 (SEM)、X射线衍射 (XRD)等分析手段 ,研究了MB8镁合金微弧氧化陶瓷膜层的生长规律 ,分析了微弧氧化条件下氧化镁膜层致密性和相结构与处理时间的关系。结果表明 ,在微弧氧化初期膜层致密 ,几乎观察不到疏松层 ;随着处理时间的延长及膜层的增厚 ,其外侧开始出现疏松层 ,最终可达到膜层总厚度的 90 %左右。膜层相结构主要由MgO、MgSiO3、MgAl2 O4和无定形相组成。随着膜层厚度的增加 ,膜层中MgO、MgAl2 O4的含量不断地增加 ,MgSiO3 的含量基本不变 ,而无定形相的含量却逐渐减少

The Research on Micromechanism and Growth Procedure of Ceramic Coating Formed by Micro-arc Oxidation on Magnesium Alloys

The regulation of ceramic coating formed by micro arc oxidation on MB8 magnesium alloys has been investigated by SEM and XRD. The relation of phase structure and compactness of MgO coating formed by micro arc oxidation with treated time has been analyzed. The results have shown that in the initial stages of micro arc oxidation the coating was compact and nearly loose coating can not be observed. With elongated treated time and increased thickness of coating, loose coating begins to appear on the coating exterior, at last the thickness can reach 90% of total thickness. The phase structure of coating was mainly composed of MgO, MgSiO 3, MgAl 2O 4 and no shape phase .As coating thickness increased, the proportion of MgO and MgAl 2O 4continually increased, the proportion of MgSiO 3 steadied, but the content of no shape phase decreased gradually.