플라즈마 전해 산화법에 의한 Al-1050 표면상의 산화막 제조에 미치는 전기적 변수의 영향 |
남경수, 송정환1, 임대영1 |
배재대학교 재료공학과 1배재대학교 정보전자소재공학과 |
Influence of the Electrical Parameters on the Fabrication of Oxide Layers on the Surface of Al-1050 by a Plasma Electrolytic Process |
Kyung-Su Nam, Jeong-Hwan Song1, Dae-Young Lim1 |
Department of Materials Engineering, Graduate School of PaiChai University 1Department of Information and Electronic Materials Engineering, PaiChai University |
|
|
|
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 $Na_2SiO_3$ (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 ${alpha}$-alumina, ${gamma}$-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. |
Key words:
PEO, ${\alpha}$-alumina, Al, Surface treatment, Electrical parameter |
|
|
|