关键词:

AZ91D镁合金, 三乙醇胺, 阳极氧化, 耐腐蚀性

Abstract:

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 g•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.

Key words:

AZ91D镁合金, 三乙醇胺, 阳极氧化, 耐腐蚀性