A Study on Surface Oxidation Coating Characteristic of Al-Si Casting Alloys

Abstract:

in this paper, it was aimed to improve understanding about the effects of physical melt treatment on the morphologies of eutectic silicon crystal size, and then the effects of these microstructural features on anodizing characteristics. A380 and A356 casting aluminum alloys were used in this experiment. A twin-screw melt-shearing process and an electro magnetic stirring process were utilized before high pressure die casting. In order to refine and homogenize the microstructure of the diecast Al-Si alloys, the melt-shearing process parameters were controlled and T6 heat treatment was carried out. A uniform microstructure over the whole thickness of the diecast specimens caused smaller difference in oxidation coating layer thickness between machined and non-machined surfaces. More uniform anodic coating layer was obtained by AC/DC coupled anodizing and PEO processes compared to conventional DC anodizing process.

• Periodical: Materials Science Forum (Volume 724)
• Pages: 173-177
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.724.173
• Online since: June 2012
• Authors: Je Sik Shin, Bong Hwan Kim, Sang Mok Lee
• Keywords: Al-Si Casting Alloy, Anodizing, Melt Treatment, Oxidation Coating

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