ABSTRACT
Microarc oxidation (MAO) coatings were produced on the Al–Cu alloys at different oxidation times. Surface morphologies, phase composition and residual stress, and wear resistance were analysed by SEM and a laser scanning confocal microscopy, X-ray diffraction, and reciprocating friction and wear tester, respectively. Increases in surface roughness, porosity, cracks, thickness, and α-Al2O3 content were found in the MAO coatings on Al–4.5Cu alloy. Presence of intermetallic Al2Cu in the Al–4.5Cu alloy improved wear resistance and induced residual compressive stress formation in the coatings. Heat accumulation of intermetallic Al2Cu was the key factor that led to the differences in coating microstructure and nature of residual stress. In addition, mechanical properties of the coated samples were slightly changed compared to that of bare Al–Cu alloys. Presence of intermetallic Al2Cu was advantageous to wear resistance and oxide film formation of MAO coated Al–Cu alloys.
Acknowledgements
The work was supported by the Fundamental Research Funds for the Central Universities (grant number N2103003 and N2003006) and National Natural Science Foundation of China (Grant number 52075087 and U1708254).
Disclosure statement
No potential conflict of interest was reported by the author(s).