Modification Research of Fluorinetitanate Conversion Coating Resistance on 6061 Aluminum Alloy

The effects ammonium fluorosilicate, complexing agent and inhibitors on the corrosion resistance of fluorinetitanate conversion coating on the surface of 6061 aluminum alloy was studied by the single factor experiment. The optimal operation parameters were as follows: NaF 3 g/L, (NH4)2SiF6 4 g/L, (NaPO3)6 1.0 g/L, titanium salt 1.5 g/L, H2O2 1.5 ml/L, pH 5.0, normal temperature, 10 minutes. SEM, EDS and polarization curves were used to invstingate the morphology and corrosion resistance of the coating. The results showed that the fluorinetitanate conversion coating was composed of continuous and compact crystal particles. The corrosion potential increased about 77 mV and the corrosion current density decreased about 80%, the corrosion resistance was improved obviously.