Reaction behavior of Ni–Re alloys during direct current polarization in sulfuric acid solutions

Resumo

The macrokinetic regularities of the reactivity of synthesized Ni–Re (20 and 60 wt %) alloys in a sulfuric acid solution (100 g/L, 25–40°C) during direct current polarization are studied using physicochemical methods. The phase composition of the synthesized alloys is determined by the formation of solid solutions as a function of the initial Ni/Re weight ratio. These are two types of nickel solid solutions (Ni₁₆Re_0.2 and Ni₁₄Re_0.9) and one rhenium solution (Ni_1.1Re). These solid solutions are anodically oxidized in the sequence of their structural rearrangement Ni₁₆Re_0.2 → Ni₁₄Re_0.9 → Ni_1.1Re with a combined transition of the metals into an electrolyte solution. These solid solutions provide the reduction of Ni³⁺ to Ni²⁺ due to the depolarization ability of rhenium, being their component.