IMPROVING ANODIC STABILITY OF AB1 (AL+1%BE) ALUMINIUM ALLOY BY DOPING WITH INDIUM

Abstract

PURPOSE. The anodic behavior of indium doped AB1 alloy is studied in the NaCl electrolyte medium in the region of indium concentration up to 0.5 wt % by a potentiostatic method. The doped alloys are demonstrated to have a more satisfactory corrosion resistance than the initial alloy AB1. METHODS. The studies are performed in the NaCl electrolyte medium using the PI-50-1.1 potentiostat. RESULTS AND THEIR DISCUSSION. Indium additions reduce the corrosion rate of AB1 alloy by 75% in the investigated media. When the indium concentration increases up to 0.5 wt % the corrosion rate of AB1 alloy decreases monotonically. It is shown that the improved corrosion resistance of AB1 alloy when doped with indium is explained by its modifying effect on the structure of the eutectic aluminum-beryllium alloy AB1, as well as by increasing the true surface of the anode or by compacting the protective phase layer of oxides with poorly soluble oxidation products. CONCLUSIONS. The conducted studies show that doping of the aluminum-beryllium alloy of eutectic composition (AB1) with indium improves its corrosion resistance, which is accompanied by a shift of the alloy free corrosion potential in the positive region.