Thermodynamic and kinetic analysis of micro-arc oxidation on magnesium alloy

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.