Barrier layer was prepared on TiAl alloy by Micro-arc oxidation(MAO) technique in silicate electrolyte,and cathodic plasma electrolytic deposition (CPED) technique was used to fabricate Al2O3 ceramiccoating on prepared TiAl alloy in Al(NO3)3 (30 g/L) ethanol electrolytes with different water content byvolume. Microstructure, composition and properties of coatings were analyzed, and mechanisms ofdifferent electrolytes were evaluated. The results showed that both arc-voltage and work voltage decreased with the increase of water content. Al2O3 CPED coatings were composed of deposition particles and cracks, and contained a-Al2O3 phase mainly and a small amount of g-Al2O3 phase. The organic reaction mechanism was studied and the performance of TiAl alloy with CPED coating under 950
C was superior to TiAl substrate.