Influence of the Electrical Parameters on the Fabrication of Oxide Layers on the Surface of Al-1050 by a Plasma Electrolytic Process

Abstract

Oxide layers were prepared by an environmentally friendly plasma electrolytic oxidation (PEO) process on an Al-1050 substrate. The electrolyte for PEO was an alkali-based solution with Na 2 SiO 3 (8 g/L) and NaOH (3 g/L). The influence of the electrical parameters on the phase composition, microstructure and properties of the oxide layers formed by PEO were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The voltage-time responses were recorded during various PEO processes. The oxides are composed of two layers and are mainly made of α-alumina, γ-alumina and mullite phases. The proportion of each phase depends on various electrical parameters. It was found that the surface of the oxides produced at a higher current density and Ia/Ic ratio shows a more homogeneous morphology than those produced with the electrical parameters of a lower current density and lower Ia/Ic ratio. Also, the oxide layers formed at a higher current density and higher Ia/Ic ratio show high micro-hardness levels.

Influence of the Duty Cycle on the Characteristics of Al2O3Coatings Formed on the Al-1050 by Plasma Electrolytic Oxidation

“…3 4,5) 최근에는 양극산화법과 비슷한 원리로 부동태 경금속 의 표면에 산화물 피막을 형성시킬 수 있는 플라즈마 전 해 산화법(PEO(Plasma Electrolytic Oxidation)) 또는 MAO (Micro Arc Oxidation))이라는 기술이 보고되고 있다. [6][7][8][9][10][11][12][13][14] 제50권 제2호(2013) )를 나타낸 것이다. Fig.…”