Influence of intermetallics on through-mask electrochemical micromachining for surface texturing of aluminum alloys

Metallic surface texturing is a key technique across a wide range of fields, including electronics, energy conversion, and fluid dynamics. Drawing inspiration from biological structures like the riblets on shark skin, known for their ability to reduce fluid drag by minimizing vortex formation, engineered textured surfaces have attracted significant attention. Despite this interest, conventional fabrication methods, such as polymeric coatings and additive manufacturing, often face limitations in durability due to mechanical degradation, resulting in high maintenance demands and reduced long-term efficiency. In this study, Through-Mask Electrochemical Micromachining (TMEMM) as a low-damage technique for fabricating microstructures on aluminum alloys, specifically AA1050, AA5005-H24, and AA2024-T3, was explored. TMEMM involves the ink-jet deposition of an insulating mask, followed by anodic polarization to etch precise microfeatures in the exposed metallic areas. Scanning electron microscopy reveals the dynamic evolution of geometric parameters during the etching process, providing critical insights into its progression. Potentiodynamic polarization evaluations further clarify the electrochemical behavior of the alloys post and during etching, showing how intermetallic particles and surface texture influence corrosion resistance and reactivity. This study underscores TMEMM's potential in enhancing surface functionalities while addressing alloy-specific challenges, offering insights for advancing textured surfaces in various technological domains.