Open AccessSelf-lubricating nanocomposite coatings using MAO to improve tribological properties of 6061 aluminum alloy
Author(s) -
Cai Hai-long,
Chao Zhang,
Hongtao Li,
Bailing Jiang
Publication year - 2021
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/abe8e6
Subject(s) - materials science , graphite , nanoparticle , nanocomposite , scanning electron microscope , alloy , microstructure , composite material , porosity , aluminium , composite number , metallurgy , tribology , nanotechnology
This study aimed to prepare self-lubricating micro-arc oxidation (MAO)/graphite composite coatings on 6061 aluminium alloy by adding graphite nanoparticles into an alkaline electrolyte during the MAO process. The microstructure, phase composition and element distribution of MAO coatings were studied using Scanning Electron Microscope (SEM), x-ray diffraction (XRD) and Energy Dispersive Spectrometer (EDS). The results showed that graphite nanoparticles can be coated uniformly in the MAO coatings, and the porosity and surface roughness of the MAO coatings were reduced by the addition of graphite nanoparticles. However, when the content of graphite nanoparticles was more than 6 g l −1 , graphite aggregation occurred. The wear resistance of the coatings was investigated using the ball-on-disk friction tester. After incorporating the graphite nanoparticles, the MAO coatings showed excellent self-lubricating properties and a reduction in the friction coefficient during the wear process. In addition, the MAO coatings showed the best result with the addition of 4 g l −1 graphite nanoparticles compared with all the other composite coatings under investigation. In conclusion, the incorporation of graphite nanoparticles improved the wear properties of the MAO coatings.