A Novel Fluorine-titanate Conversion Process on 6061 Aluminum Alloy Surface

A chromium-free conversion coating on 6061 aluminum substrate was prepared from a conversion solution containing titanate and sodium fluoride. The uncorroded area fraction of the sample after salt spray test was served as the index to study the effect of the composition of conversion solution and process parameters on the corrosion resistance of conversion coating. The optimized process parameters of fluorine-titanate conversion are as follow: titanium salt 1.5 g/L, sodium fluoride 3 g/L, hydrogen peroxide1.5 mL/L, normal temperature, pH=5.0, and conversion time 10 min.