科研之友
微信
新浪微博
Facebook
分享链接
摘要
A study investigated the formation and microstructural features of the oxide layer formed on Mg-9 wt%Al-1 wt%Zn alloy coated by two-step plasma electrolytic oxidation (PEO) where an acid electrolyte with K2ZrF6 was used for the second PEO coating after the initial coating was done in an alkaline electrolyte. The microstructure, chemical compositions, and constituent compounds of the oxide layers were observed using scanning electron microscopy, electron probe micro-analyzer, and X-ray diffraction, respectively. The microstructural observations showed that the micropores caused by plasma discharge were formed in the oxide layers which were comprised of three different parts, namely, inner, intermediate, and outer layers from the substrate to the surface of the sample. The outer layer contained the highest concentration of Zr element whose amount decreased toward the substrate whereas the concentration of Mg element increased in the order of outer, intermediate, and inner layers. This finding suggested that the outer oxide layer was mainly comprised of ZrO2 compound while both ZrO2 and Mg2Zr5O12 compounds existed together as the main compounds in the intermediate oxide layer.
- 出版日期2014-12-5
