STUDY THE EFFECT OF COATING USING NANOPARTICLES ON THE CORROSION OF ALUMINUM ALLOY IN DIFFERENT SOLUTIONS

Corrosion resistance of metals is one of the most important topics for researchers. In this work, epoxy-TiO2 nanocomposite has been developed for protection of 6061AL alloy. The dip-coating technique used to deposit the coating on 6061 Al alloy substrate. Different concentrations of TiO2 NPs (1,3,5 )Wt% have been used to study the corrosion behavior in 3.5% NaCl medium. Also, 200,150 and 100 mm/min dipping speeds have been employed for 1%wt TiO2 to show their effects on coating layer and corrosion rate. Characterization of coated surfaces were investigated by AFM, FESEM andEDS,while theelectrochemical measurementswas using to evaluate protective nature of the coating. The results have shown that the corrosion rate has decreased with 1wt% of TiO2 NPs concentration. The corrosion rate (mm/y) of (7.131×10-4, 1.803×10-3 and 8.183×10-3) have been obtained with (1 , 3 and 5 wt% TiO2) respectively. The results have been confirmed by using a constant dip-coating speed of 200 mm/min, and the results of the corrosion rate for 200,150 and 100 mm/min have been 7.131×10-4, 7.984×10-4and 8.293×10-4 respectively. The morphology of coating film which characterized by SEM, have shown that the TiO2 NPs spread and was covered by epoxy very well. The AFM test used to study the surface average roughness of coating film where the Ra for sample with epoxy coating is24.4 nm and for sample with (epoxy _1%wt TiO2) is 1.508 nm.