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.