Wear resistance of ceramic coating on AZ91 magnesium alloy by micro-arc oxidation
(1.辽宁省沈阳市沈阳工业大学材料科学与工程学院
2.辽宁省沈阳市沈阳理工大学材料科学与工程学院
3.School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110023, China
4.College of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110023, China
5.Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)
2.辽宁省沈阳市沈阳理工大学材料科学与工程学院
3.School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110023, China
4.College of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110023, China
5.Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)
Abstract: The ceramic coating formed on AZ91 magnesium alloy by micro-arc oxidation (MAO) was characterized. The results show that the ceramic coating（3.4-23 μm in thickness）on the surface of AZ91 alloy was attained under different micro-arc oxidation treatment conditions, which consist mainly of MgO, Mg2SiO4 and MgSiO3 phases. Nano-hardness in a cross-sectional specimen was determined by nano-indentation experiment. The MAO coatings exhibit higher hardness than the substrate. Dry sliding wear tests for the MAO coatings and AZ91 alloy were also carried out using an oscillating friction and wear tester in a ball-on-disc contact configuration. The wear resistance of the MAO coatings is improved respectively under different treatment time as a result of different structures of ceramic coatings formed on AZ91 alloy.
Key words: AZ91 alloy; magnesium alloy; ceramic coating micro-arc oxidation; wear resistance