Fluoroborate Corrosion Inhibitor For Aluminum Development

The corrosion velocity and corrosion inhibition efficiency of many kinds of compound for aluminium in 5% fluoboric acid was studied using the weight-loss method, then some kinds of compounds with certain corrosion inhibition effect have been got in 5% fluoboric acid solution. In these compounds cinnamy aldehyde, butyne diol, furan-formaldehyde and sodium tripolyphosphate are selected as research object. Their corrosion inhibition action for aluminium was studied with different temperatures in 5% fluoboric acid by adsorption theory and electrochemical polarization-curve method, the mechanism of corrosion inhibition action was analyzed and the thermodynamic functions during the adsorption process. The results indicated that the single molecule layer of these compounds adsorbed on the surface of aluminium and almost followed Langmiur isothermal equation. The adsorption procedure of cinnamy aldehyde , butyne diol , furan-formaldehyde and sodium tripolyphosphate was a heat-absorbing reaction. The adsorption ability and corrosion inhibition efficiency increased when temperature increased. Cinnamy aldehyde and sodium tripolyphosphate are cathodic type inhibitor. Butyne diol and furan-formaldehyde are mixed type inhibitor. The corrosion current was decreased by them in different degree.A composite and excellent corrosion inhibitor was composed by orthogonal method. The corrosion inhibition action of this composite corrosion inhibitor has been evaluated by using weight-loss method, electrochemical polarization-curve method and scanning electron microscopy techniques. The corrosion rate of aluminium in fluoboric acid has been determined with different concentration of 5% fluoboric acid, different temperature and different time. The SEM photos indicated that no signal of was found under different corrosion condition. It shows that the composite corrosion inhibitor is an excellent corrosion inhibitor for aluminium in 5% fluoboric acid solution.