Investigation of the effect of cryogenic processes on the corrosion behavior of AA5083-H111 alloy in 3,5% NaCI environment

Aluminum is a metal that has seen frequent use recently in many applications in the industrial sector because of its desirable properties. Many industries prefer aluminum because of its high mechanical resistance, electrical and thermal conductivity, high corrosion resistance, and lower weight compared to other metals. The cryogenic process is more economical compared to other heat treatments and at the same time, it is a very effective heat treatment for improving various mechanical properties of metals. This method has recently begun to be applied to aluminum. Although corrosion is an oxidation mechanism that is difficult to control, this control becomes a necessity in the maritime sector. Aluminum alloys with higher corrosion resistance than other alloys are preferred in this sector. The AA5083-H111 alloy has higher corrosion resistance compared with other aluminum alloys. For this reason, AA5083-H111 alloy is widely used in the maritime industry. The purpose of this study was to investigate the corrosion mechanism of AA5083-H111 alloy subjected to -80 °C shallow cryogenic processing and to observe the effect of this process on the surface hardness of the metal. In this study, shallow cryogenic treatment was applied to the 6 mm-thick AA5083-H111 alloy at -80 °C for 10, 24, 36, 48, and 72 h. Before and after the cryogenic process, the corrosion mechanism of the alloy was investigated via electrochemical impedance spectroscopy (EIS) in a 3,5% NaCl environment. The hardness values of the alloy before and after the experiments were analyzed by Brinell hardness measurement. In addition, after the corrosion experiments, morphological changes on the surface of the alloy were observed using scanning electron microscopy (SEM), atomic force microscopy (AFM), and optical profilometer (OP) techniques. When the findings were examined, it was seen that the effect of the shallow cryogenic process was insufficient for improving the corrosion resistance of the AA5083-H111 alloy in a 3.5% NaCl solution.