Enhancement of coating characteristics via improved plasma electrolytic oxidation set-up

The plasma electrolytic oxidation process involves high-temperature operations and exposed to corrosive chemicals. Thus it requires stringent experimental set-up to produce uniform and high-quality coatings. This study proposes an enhancement to the current plasma electrolytic oxidation experimental set up to improve: 1) electrode holder; 2) cathode-anode electrodes, and 3) water-cooling system. In this paper, the focus is dedicated to the first two items. For the first item, the redesigned electrode holder is developed using 3-dimensional software. For the second item, results due to cathode via stainless container as well as carbon electrode are discussed. The performance of the new set-up plasma electrolytic oxidation is compared with the old one by analysing the microstructure and the mechanical properties of titanium dioxide coatings formed on a titanium aluminium vanadium alloy substrate using both set-ups. Surface morphology shows that the coating produced using the new set-up is thicker, denser and has lower porosity as compared to the coating deposited using the old set-up. The mechanical properties of hardness and adhesive strengths of the coating are also improved in the new set-up. Thus, the use of this set-up is recommended for improved coating performance to produce a uniform coating having enhanced mechanical performance.