Influence of the Cathodic Pulse on the Formation and Morphology of Oxide Coatings on Aluminium Produced by Plasma Electrolytic Oxidation / Wpływ Impulsu Katodowego Na Tworzenie I Morfologie Warstw Tlenkowych Na Aluminium Otrzymywanych Na Drodze Plazmowego Utleniania Elektrolitycznego

Archives of Metallurgy and Materials

S. Pietrzyk¹  W. Gebarowski¹ 

[1] AGH UNIVERSITY OF SCIENCE AND TECHNOLOGY FACULTY OF NON-FERROUS METALS, 30-059 KRAKÓW, AL. MICKIEWICZA 30, POLAND

关键词: Keywords: Plasma electrolytic oxidation;    PEO;    Alumina coatings;    Aluminium oxide;   

DOI  :  10.2478/v10172-012-0180-7

学科分类：金属与冶金

来源: Akademia Gorniczo-Hutnicza im. Stanislawa Staszica / University of Mining and Metallurgy

【 摘 要 】

Plasma electrolytic oxidation (PEO) is an effective method to obtain hard ceramic coatings on Al, Mg and Ti alloys. Micro-discharges occurring on the electrode surface during process promote the creation of crystalline oxides phases which improve mechanical properties of the coating. By using alternate current (AC) at some current conditions the process can be conducted in ‘soft’ spark regime. This allows producing thicker layers, increasing growth rate and uniformity of layer, decreasing amount of pores and defects. These facts proof the importance of cathodic pulse in the PEO mechanism; however its role is not well defined. In this work, influence of anodic to cathodic current density ratio on kinetics of coating growth, its morphology and composition were investigated. The PEO process of pure was conducted in potassium hydroxide with sodium metasilicate addition. The different anodic to cathodic average currents densities ratios of pulses were applied. The phase composition of coatings was determined by XRD analysis. Morphology of obtained oxide layers was investigated by SEM observations.

【 授权许可】

Unknown