Time-Dependent Growth Behavior of Alumina Layers on Aluminum during plasma-Assisted Electrochemical Oxidation in a Plasma–Liquid Interface

Dehghani, Zohreh

doi:10.22075/ppam.2026.41478.1236

Time-Dependent Growth Behavior of Alumina Layers on Aluminum during plasma-Assisted Electrochemical Oxidation in a Plasma–Liquid Interface

Document Type : Original Article

Author

Zohreh Dehghani

Plasma and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute, Tehran, Iran

10.22075/ppam.2026.41478.1236

Abstract

Surface modification of aluminum by plasma-assisted electrochemical techniques has attracted considerable interest due to their ability to produce oxide layers with enhanced surface properties. In this study, aluminum surfaces were treated using a DC microplasma-assisted electrochemical process in a 0.05 M NaOH electrolyte under atmospheric-pressure conditions. The effect of treatment duration on oxide-layer development was investigated by varying the processing time from 5 to 20 min while maintaining constant discharge parameters. Surface morphology and roughness were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM), and phase composition was analyzed using X-ray diffraction (XRD). AFM results showed that surface roughness increased with treatment time and reached a maximum after 10 min, indicating accelerated oxide growth. Further treatment led to a reduction in roughness, suggesting surface reorganization during prolonged plasma exposure. SEM observations revealed the formation of porous, interconnected needle-like oxide structures on the treated surface. XRD analysis confirmed the formation of crystalline γ-Al₂O₃ after 20 min of treatment. Based on the experimental findings, a three-stage growth mechanism involving oxide nucleation, oxide growth, and plasma-assisted surface reorganization was proposed. The results demonstrate that treatment duration is a key parameter governing the structural evolution of alumina layers formed in plasma–liquid systems and provide insight into the controlled modification of aluminum surfaces by microplasma-assisted electrochemical oxidation.

Keywords

Aluminum, Plasma&ndash

liquid interaction, Surface modification, AFM, SEM

Subjects

Nanoscale Materials and Structures: Fabrication and Characterization

© 2026 The Author(s). Progress in Physics of Applied Materials published by Semnan University Press. This is an open access article under the CC-BY 4.0 license. (https://creativecommons.org/licenses/by/4.0/)

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