Non-sparking anodization process of AZ91D magnesium alloy under low AC voltage

作者：Li Weiping^*; Li Wen; Zhu Liqun; Liu Huicong; Wang Xiaofang

来源：Materials Science and Engineering B-Solid State Materials for Advanced Technology, 2013, 178(7): 417-424.

DOI：10.1016/j.mseb.2013.01.008

• Anodization
• AZ91D
• Film morphology
• Microstructure

Anodization is widely recognized as one of the most important surface treatments for magnesium alloys. However, since high voltage oxidation films are limited in some applications due to porosity and brittleness, it is worthwhile to explore the non-sparking oxidizing process. In this work, AZ91D was electrochemically anodized at different AC voltages in an electrolyte containing 120 g/L NaOH and 80 g/L Na2SiO3 center dot 9H(2)O. The effects of voltage on the surface morphology, composition and reaction process, especially the non-sparking discharge anodic film formation process, were investigated. The results showed that four different processes would appear according to the applied voltage variation from 6V to 40V, and that the non-sparking film formation process occurred in the range of 6-10 V. The film formed on the AZ91D surface under 10V AC was mainly composed of Mg2SiO4 with a lamellar structure. The horizontal and vertical expansion of the lamellar structure resulted in the formation of a multi-layered structure with a stable, linear growth rate for 30 min. The non-sparking film formation process can be considered to be the result of a balance of electrochemical dissolution and chemical deposition reaction.

• 出版日期2013-4-20
• 单位北京航空航天大学; 中国航空工业集团公司北京航空制造工程研究所