Oxidation Behavior of the Micro-arc Oxidation Scale of Al on TC4 Titanium Alloy

Abstract

Abstract. In this paper, Al coatings were deposited on the TC4 Titanium alloy by arc ion plating, and hence the Al coatings were micro-arc oxidized (MAO) in the solution of Na2SiO3 + (NaPO3)6 for 20min, 60min and 90min, respectively. The microstructure and oxidation behavior at 700 o C in air for 100 h were investigated by SEM/EDS, XRD and electric balance. The results show that with the increase of MAO treated time, the acquired scales became coarser, and their main composition was rich in Al2O3. After the 10 hours of the initial oxidation at 700 o C in air, obvious peeled scales were appeared on the samples of MAO treated for 20 min and 90min. After oxidation for 40 h, the samples of MAO treated for 60 min occurred mass lose. The oxidation mechanism of the MAO treated TC4 alloy was discussed.