The effect of triethanolamine concentrations on the properties of anodizing film of AZ91D magnesium alloy was investigated by using constant current anodizing technique in electrolyte containing KOH

Na2SiO3

Na2B4O7 and triethanolamine etc.Properties of the anodizing coatings were evaluated by voltage-time curves

corrosion rate and polarization curves and the coating morphologies were characterized by using SEM.Experimental results revealed that triethanolamine has remarkable effect on arc restraining

which resulted in an increase in the anodizing film thickness and a decrease in the surface micro-hole size

and finally the improvement in the surface finish.The anodizing film obtained by anodic oxidation in a solution containing 30 g8226;dm-3 triethanolamine has good corrosion resistance.During the anodic oxidizing process

triethanolamine molecules are adhered by chemisorption to the surface of the magnesium alloy

through which the adsorption ability and the number of oxygen bubbles on the alloy surface decreased.Hence

the porosity of the obtained ceramic film is reduced

and the film density as well as its corrosion resistance is improved.