Inhibition effects of PMA/SbBr_3 complex inhibitor on copper and copper-nickel alloy in LiBr solutions

The effects of PMA/SbBr3 inhibitor on copper and copper-nickel alloy in 55%LiBr solution were investigated by chemical immersion and electrochemical measurements. The results indicate that in boiling 55%LiBr solution containing PMA/SbBr3 inhibitor, corrosion rates of copper and copper-nickel alloy are 67.48μm/a and 38.14μm/a, respectively. Since both anodic and cathodic electrochemical reactions can be inhibited, PMA/SbBr3 belongs to complex inhibitor. PMA has the effect of inhibiting hydrogen evolution and [PMo<sup>12 O<sup>40 ]3- , the anion of PMA, has a strong oxidizing effect. Sb3+ also shows an oxidizing effect. It may exist in LiBr solutions stably with PMA. Because of the synergistic effect of PMA and Sb3+ , a protective film, comprising CuO, Cu2O and Sb, formed on copper and copper-nickel alloy surface may prevent Br-from diffusing to the surface of metals. As a result, the anticorrosion performance of copper and copper-nickel alloy may be improved.

The effects of PMA/SbBr_3 inhibitor on copper and copper-nickel alloy in 55%LiBr solution were investigated by chemical immersion and electrochemical measurements. The results indicate that in boiling 55%LiBr solution containing PMA/SbBr_3 inhibitor, corrosion rates of copper and copper-nickel alloy are 67.48μm/a and 38.14μm/a, respectively. Since both anodic and cathodic electrochemical reactions can be inhibited, PMA/SbBr_3 belongs to complex inhibitor. PMA has the effect of inhibiting hydrogen evolution and [PMo_~12 O_~40 ]~3- , the anion of PMA, has a strong oxidizing effect. Sb^3+ also shows an oxidizing effect. It may exist in LiBr solutions stably with PMA. Because of the synergistic effect of PMA and Sb^3+ , a protective film, comprising CuO, Cu_2O and Sb, formed on copper and copper-nickel alloy surface may prevent Br-from diffusing to the surface of metals. As a result, the ~anticorrosion performance of copper and copper-nickel alloy may be improved.