Influence of process parameters of oxygen cold plasma treatment on wettability ageing time of 2024 aluminium alloy

Abstract 2024 aluminium alloy is widely used in aeronautical applications because it provides a high mechanical strength and low weight. Aeronautical critical environmental conditions cause corrosion on the surface in part, due to the Cu present in Al2024. To solve problems associated with corrosion, the aluminium alloy surface is commonly covered by paint; it is important to guarantee the adhesion of the paint coating to the aluminium alloy and the stability of the coating in the course of time. To achieve this aim the surface must be prepared before applying a protective coating. Cold plasma treatment represents an efficient, non-polluting and economical alternative to clean and activate aluminium surfaces. In particular, it has been demonstrated that an oxygen cold plasma treatment improves wettability and adhesion of the Al2024 surface. The aim of this work has been to value the wettability ageing time of Al2024 surfaces treated with oxygen cold plasma. The evaluation of the ageing time represents a fundamental step to plan the insertion of the plasma process inside an industrial process. In fact, once the ageing time has been determined, it is possible to establish how much time has to pass between the surface activation of a body, obtained by cold plasma treatment, and the following paint process.