Achieving excellent anti-corrosion and tribological performance by tailoring the surface morphology and chemical composition of aluminum alloys

Abstract

Aluminum alloy surfaces with micro/nano-structures were fabricated via a simple chemical etching (CE) method. After chemical modification with perfluorodecyltriethoxysilane (PFDS), n-octadecyltriethoxysilane (OTS) and aminopropyltriethoxysilane (APS), surfaces with different wettability were obtained. The morphology and chemical elements of the as-prepared surfaces were investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). In addition, the influence of the surface morphology and chemical modification on the wetting/dewetting properties was investigated. Finally, the anti-corrosion and tribological properties of the as-prepared self-assembled monolayers (SAMs) were characterized using an electrochemical workstation and UMT-3 tribometer. The influence of surface morphology and SAMs on the anti-corrosion and tribological performances is discussed in detail. The results showed that the optimal preparation conditions consisted of a 40% volume fraction of hydrochloric acid with a CE time of 2 min. The corrosion resistance of the surfaces chemically modified with hydrophobic groups was much better than that of those modified with hydrophilic groups. Also, the combination of micro/nano-structures and suitable SAMs on aluminum alloy surfaces could greatly enhance the friction reduction and wear resistance behavior.