Plasma Electrolytic Oxidation in Surface
Modification of Metals for Electronics

Sharma, Mukesh Kumar; Jang, Youngjoo; Kim, Jongmin; Kim, Hyungtae; Jung, Jae Pil

doi:2014.32.3.241

J Weld Join > Volume 32(3); 2014 > Article

Special Issue

Journal of Welding and Joining 2014;32(3):241-247.
DOI: https://doi.org/10.5781/JWJ.2014.32.3.27 Published online June 30, 2014.

Plasma Electrolytic Oxidation in Surface Modification of Metals for Electronics

Mukesh Kumar Sharma^*, Youngjoo Jang^*, Jongmin Kim^**, Hyungtae Kim^**, Jae Pil Jung^*,†

Correspondence: Jae Pil Jung,
Email: jpjung@uos.ac.kr

Abstract

This paper presents a brief summary on a relatively new plasma aided electrolytic surface treatment process for light metals. A brief discussion regarding the advantages, principle, process parameters and applications of this process is discussed. The process owes its origin to Sluginov who discovered an arc discharge phenomenon in electrolysis in 1880. A similar process was studied and developed by Markov and coworkers in 1970s who successfully deposited an oxide film on aluminium. Several investigation thereafter lead to the establishment of suitable process parameters for deposition of a crystalline oxide film of more than 100μm thickness on the surface of light metals such as aluminium, titanium and magnesium. This process nowadays goes by several names such as plasma electrolytic oxidation (PEO), micro-arc oxidation (MOA), anodic spark deposition (ASD) etc. Several startups and surface treatment companies have taken up the process and deployed it successfully in a range of products, from military grade rifles to common off road sprockets. However, there are certain limitations to this technology such as the formation of an outer porous oxide layer, especially in case of magnesium which displays a Piling Bedworth ratio of less than one and thus an inherent non protective oxide. This can be treated further but adds to the cost of the process. Overall, it can be said the PEO process offers a better solution than the conventional coating processes. It offers advantages considering the fact that he electrolyte used in PEO process is environmental friendly and the temperature control is not as strict as in case of other surface treatment processes.

Key Words: Plasma electrolytic oxidation, Micro-arc oxidation, Aluminum, Magnesium, Electronics