Effects of current frequency on the MAO coatings on AA7050. (2nd August 2020)

• Record Type: Journal Article
• Authors: Zong, Y.; Song, R. G.; Hua, T. S.; Cai, S. W.; Wang, C.; Li, H.
• Is Part Of: Surface engineering. Volume 36:Number 8(2020)
• Page Start: 809
• Page End: 816
• Publication Date: 2020-08-02
• Subjects: 7050 high-strength aluminium alloy -- micro-arc oxidation -- current frequency -- microstructure -- property; Surfaces (Technology) -- Periodicals; Coatings -- Periodicals; 620.4405
• DOI: 10.1080/02670844.2019.1596577
• Languages: English
• ISSNs: 0267-0844

Abstract

ABSTRACT: In order to solve the corrosion and wear of 7050 aluminium alloy (AA7050) caused by the marine environment and prepare excellent coating structure to prolong its service life, the micro-arc oxidation (MAO) ceramic coatings were prepared at the current frequency of 50, 250, 500, 750, 1000 Hz in the silicate electrolyte, respectively. To analyse the surface morphology, phase composition, corrosion resistance and wear resistance of ceramic coatings, the scanning electron microscopy (SEM), X-ray diffraction (XRD), electrochemical workstation, friction-abrasion tester were used. The results showed that when the current frequency was too low, the mono-pulse energy would be too high and the surface of MAO ceramic coating would be rough, which affected the compactness of the coating. Nevertheless, when the current frequency was too high, it will be unfavourable to the growth of MAO ceramic coating, and the corrosion resistance and wear resistance of the as-prepared coatings were poor.