Assessment of the surface reactivity of AA1050 aluminium alloy

Abstract

During processing from cast slab to thin gauge material, the AA1050 aluminium alloy proceeds through various stages of thermomechanical processing, with the conditions at each processing stage influencing the microstructure of the final coil. The reactivity of the material in defined chemical and electrochemical processes has been demonstrated as a useful method to describe variance in the microstructure and surface chemical properties of the aluminium. Various techniques have been employed to assess the reactivity of the surface, e.g. sodium hydroxide etching and open circuit potential measurements. Etching in hydrochloric acid was also carried out on samples that had been previously alkaline etched. The weight losses in both alkaline and acid solutions were measured, and the surface responses were examined and analysed using scanning electron microscopy and white light interferometry. Visible and measurable differences in the sample surfaces were observed. Finally, the novel state-of-the-art technique of in-SEM 3D electron tomography was used to characterize the near-surface microstructure in a way that has not previously been possible for such a representative volume.

Effects of different surface cleaning procedures on the superficial morphology and the adhesive strength of epoxy coating on aluminium alloy 1050

“…In addition, the intermetallic particles i.e. Fe and Si concentrations significantly decreased after acid cleaning indicating the intermetallic particles removal from the surface [5,10,18,22,23]. The decrease of O and the increase of Al on the sample cleaned by method 3 can be described by Eqs.…”

“…1c 1 and c 2 ). The surface cavities can be associated with dropping out of the intermetallic particles from the surface due to the local dissolution of the aluminium alloy matrix surrounding them [1,5,10].…”

“…AA1050 aluminium alloy, which represents the commercially pure aluminium, has been used in the conventional engineering applications where the corrosion resistance is required and the mechanical strength is relatively unimportant (e.g., architectural, automotive industries and containers and equipment for the food and chemical industries). However, it can undergo localized pitting corrosion due to the presence of some alloying elements such as iron (Fe) and silicon (Si) [10,11]. Therefore, the improvement of the AA1050 corrosion resistance has been a topic of great importance.…”

Properties of aluminum oxide thin film obtained by metal plasma immersion ion implantation and deposition after zirconium-based pretreatment

“…Next, deposition starts at the intermetallics which are preferable sites for the onset of the cathodic reactions involved in the formation of the converted layer. Cathodic intermetallics have been identified even in commercially pure Al such as 1050 and 1100 alloys [10,11]. Thus, similar film formation mechanism can be expected for these materials.…”

Electrochemical investigation of the epoxy nanocomposites containing MnAl2O4 and CoAl2O4 nanopigments applied on the aluminum alloy 1050

“…The intermetallic particles exhibit cathodic activity relative to the aluminum matrix. [1][2][3][4] Therefore, they are catalytic sites for the cathodic reactions and nucleation of pits. [5][6][7] AA1050 has been used in conventional engineering applications, i.e., architectural, automotive industries, containers, and equipment for the food and chemical industries, where corrosion resistance is required and the mechanical strength is relatively unimportant.…”