Thermodynamic and kinetic analysis of micro-arc oxidation on magnesium alloy
CHEN Xian-ming, LUO Cheng-ping, LIU Jiang-wen, LI Wen-fang (College of Mechanical Engineering, South China University of Technology, Guangzhou 510641, China)
Thermodynamic and kinetic analyses of the micro-arc oxidation(MAO) on magnesium alloy were made . The result indicated that the reactions producing the phases in the coating were thermodynamically possible, and the formation of the MAO film was not a typical nucleation and growth process. A thin oxide film was first formed on the alloy surface by the electrolyte and an MAO coating was finally generated via repeated breakdown, reformation, sintering, ejection and pile-up of the films. The formation of film appeared to be controlled by such process variables as voltage, current, electrolyte system and pH value of the solution.