Effect of magnesium in aluminum alloys on characteristics of microarc oxidation coatings
(1.Key Laboratory of Automobile Materials, Ministry of Education, College of Materials Science and Engineering,Jilin University, Changchun 130025, China
2.吉林省长春市吉林大学汽车材料系材料科学与工程系重点实验室)
2.吉林省长春市吉林大学汽车材料系材料科学与工程系重点实验室)
Abstract: Microarc oxidation(MAO) coatings were prepared on the surface of aluminum alloys with different contents of magnesium. The morphologies and surface roughness of the coatings were characterized by Confocal laser scanning microscopy(CLSM). Phase and chemical composition of the MAO coatings were analyzed by X-ray diffractometry(XRD) and X-ray photoelectron spectroscopy(XPS). The experimental results show that the coatings formed on different substrates have two-layer morphologies and are mainly composed of Al2O3 and Al-Si-O phases. In addition, the content of Al2O3 increases with increasing the content of magnesium. XPS results prove that magnesium from substrate indeed participates in the MAO process and is incorporated into the coating in the form of MgO. The coating formed on Al-3Mg substrate has the smallest mass loss and the lowest friction coefficient of 0.17？0.19.
Key words: microarc oxidation; magnesium; alloying element; friction; wear; aluminum alloy