Antibacterial and Corrosion Resistance Properties of Anodized AA6061 Aluminum Alloy

Abstract

Anodizing is one of the surface treatments for aluminum and its alloys. It is commonly used to increase corrosion resistance and mechanical properties. This technique is also applied for decorative purpose. Therefore, anodized aluminum alloys are widely used in many applications such as household structure, cell-phone case, automobile and aircrafts. Anodic aluminum oxide (AAO) structure, which has a pore at the center of each hexagonal cell arrangement, is created after anodizing process. To further enhance the property of anodized aluminum alloys, antibacterial property can be produced on AAO surface by deposition of nanoparticles into its pore structure. In this work, AA6061-T6 aluminum alloy was anodized at 12 V using 20%w/v H2SO4 at temperature of 17±1°C for 30 minutes. AgNO3 solution was used for producing Ag nanoparticles. Effects of AgNO3 concentrations on antibacterial and corrosion resistance properties of anodized AA6061 aluminum alloy were studied. Antibacterial property was investigated on both gram-positive (S.aureus) and gram-negative (E.coli) bacteria according to JIS Z 2801 standard test for three months after exposure to ambient environment. 100% reduction of S.aureus was achieved, whereas 97.3% reduction of E.coli was obtained when using 1mM AgNO3. However, the deposition of Ag nanoparticles resulted in a slight increase in corrosion susceptibility.

Anodized Aluminum Surface with Topography-Mediated Antibacterial Properties

“…Aluminum is a very attractive material for engineering construction, and many aluminum components are used in medical devices and in frequently touched surfaces . Nonetheless, reported antibacterial aluminum surfaces have been limited to those that incorporate leachable antibacterial agents (quaternary ammonium salts or metallic silver and copper) − or passivated with low surface energy molecules to create superhydrophobic surfaces . Interestingly, recent reports indicate that aluminum can be transformed into antibacterial surfaces by inducing micronanoscale topographical patterns (without the need for antibacterial coatings) via low cost chemical etching processes. , Surprisingly, only a few studies have focused on the study of topography-mediated antibacterial aluminum prepared by a chemical etching process. ,, Hasan et al reported antiviral aluminum surfaces fabricated using a chemical etching process, which were effective against the current SARS-CoV-2.…”

Facile Route to Effective Antimicrobial Aluminum Oxide Layer Realized by Co-Deposition with Silver Nitrate

“…The first studies related to the deposition of silver on anodized aluminum surfaces date back to about 20 years ago: the electrodeposition of silver seemed to improve the antibacterial activity of anodized aluminum [55], paving the way for new types of antibacterial surfaces. In recent years, silver has been deposited on the anodized layer by the electroless deposition method [56][57][58], but also by exploiting alternative techniques, such as hydrothermal deposition [59] or via the photoreduction deposition method [59]. However, Dehghan et al [60] developed a simple process of co-deposition of silver powder with alumina during the anodizing step.…”

Evaluation of the electrochemical performance of Ag containing AAO layers after extended exposure to a model corrosive medium

“…MIC is an electrochemical process where micro-organisms can initiate, facilitate or accelerate corrosion reactions through interaction among the components of the metal-solution-microorganisms system [17]. According to recent research, MIC can appear in various media [18,19], including water supply and irrigation pipe systems [19], marine environments [20], in both tropic [20] and arctic [21] conditions, also in fuel tanks [22,23], etc. Figure 1 presents a schematic illustration of localized MIC on aluminum alloy, according to the concepts described in [14].…”