Corrosion Resistance of Phytic Acid/Benzotriazole Composite Conversion Film on a Copper Surface

Phytic acid (PA) benzotriazole composite conversion films with different concentrations of BTA were prepared by an impregnation method, and their wettability, microstructure, and corrosion resistance were studied. The results showed that when the BTA content was 1.6 wt %, the maximum water contact angle of the conversion film reached 137.5°, and the corrosion current density reached a minimum of 1.610 × 10^–7 A/cm². The salt spray and corrosive liquid environments experimental results also showed that the synergistic effect of PA and BTA was the best when the BTA concentration was 1.6 wt %. Hydrogen bonds are formed between PA chelates and BTA chelates enhancing the density of the conversion film leading to the improvement of corrosion resistance of conversion film on a copper surface with the introduction of BTA.