Застосування методу поляризаційного опору для моніторингу корозії алюмінієвих сплавів

Abstract

The problem of the resource of bearing structures from aluminum and its alloys is one of the priorities in modern technology, since atmospheric corrosion causes up to 85% of damages. Therefore, the development of corrosion monitoring systems for the aggressiveness of the internal compartments of aircrafts is an important problem. Known sensors for such corrosion monitoring systems are based on the measuring of polarization resistance method. In such sensors, electrodes of noble metals (for the determination of moisture) and alloys used in aircraft engineering are most often used. The purpose of the work is to investigate the corrosion polarization resistance of common aluminum alloys D16T and D1T in aqueous solutions of different composition for modeling and facilitating the interpretation of results in tests of corrosion sensors under conditions of moisture condensation. It is shown that the change of the polarization resistance in time, depending on the composition of the medium and the type of material, adequately reflects the corrosion resistance of alloys D16T and D1T, which are similar in properties. It was established that reduction of corrosivity of solutions of sodium sulfate with decrease in their concentration causes more significant increase of polarization resistance on D1T compared to D16T. This can be explained by the doubly lower content of magnesium in the D1T alloy compared to D16T. It was observed an unexpected increase in polarization resistance in the presence of hydrocarbonates. An explanation of this phenomenon requires further research, since such electrolytes are present at atmospheric corrosion of structures near internal combustion engines.