The Corrosion Performance of Al-Si and Al-Cu Casting Alloys in Hlus-plus"> lus-plus">2 SOlus-plus"> lus-plus">4 lus-plus">and Nalus-plus"> lus-plus">2 COlus-plus"
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- 作者：Amr S. Ismail ; Mohamed A. Abbas
- 关键词：Corrosion ; Aluminium alloys ; Morphology ; H2SO4 ; Na2CO3
- 刊名：Silicon
- 出版年：2017
- 出版时间：March 2017
- 年：2017
- 卷：9
- 期：2
- 页码：193-199
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Inorganic Chemistry; Materials Science, general; Optics, Lasers, Photonics, Optical Devices; Environmental Chemistry;
- 出版者：Springer Netherlands
- ISSN：1876-9918
- 卷排序：9
文摘
This paper focuses on corrosion performance of aluminium-silicon (Al-Si 7 %) and aluminium-copper (Al-Cu 15 %) alloys, produced locally by a casting process, under different conditions of media and temperatures. The selected media are acidic (10 % H2SO4solution) and alkaline (10 % Na2CO3 solution). The corrosion experiments used weight loss and corrosion penetration rate within interval immersion periods of 5 hours. The surface morphology was studied using optical and scanning electron microscopes (SEM). It was observed that, Al-Si 7 % alloy shows less of weight loss and higher corrosion resistance in 10 % H2SO4 and 10 % Na2CO3solutions rather than Al-Cu 15 % alloy at room temperature. The corrosion clearly increased and the attack was more significant at 50 °C. Moreover, corrosion rate values of Al-Si and Al-Cu alloys are higher in H2SO4medium, due to the hydrogen enhancement for the cathodic reaction, than in alkaline medium. This result relates to the formation of Al-Si and Al-Cu oxide surfaces. On the other hand, the surface morphology of the Al-Cu alloy shows that there are clear colored SO42− and CO32− precipitates formed after 5 hours immersion, whereas this behavior does not appear on the Al-Si alloy surface. SEM images show that the corrosion performance increased mainly in the acid medium rather than the alkaline one in which the pores produced on the Al-Si surface may contribute to a decline of sites in the oxide surface.