Microstructure and properties of ceramic coatings produced on 2024 aluminum alloy by microarc oxidation

Citation
Wb. Xue et al., Microstructure and properties of ceramic coatings produced on 2024 aluminum alloy by microarc oxidation, J MATER SCI, 36(11), 2001, pp. 2615-2619
Citations number
15
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
JOURNAL OF MATERIALS SCIENCE
ISSN journal
0022-2461 → ACNP
Volume
36
Issue
11
Year of publication
2001
Pages
2615 - 2619
Database
ISI
SICI code
0022-2461(2001)36:11<2615:MAPOCC>2.0.ZU;2-7
Abstract
The microstructures of the microarc oxidation coatings and 2024 aluminum al loy substrate were observed using the scanning electron microscope (SEM) an d the phase composition of the coatings was analyzed by X-ray diffraction ( XRD). Furthermore, the profiles of the nanohardness, H, and elastic modulus , E, along the coating depth were first determined using the mechanical pro perties microprobe. The microarc oxidation coatings consist of two layers-a loose layer and a compact layer. The H and E in the compact layer are abou t 18-32 GPa, 280-390 GPa, respectively. The H and E profiles are similar, a nd both of them exhibit a maximum value at a same depth of the coatings. Th e distribution of alpha -Al2O3 phase content determines the H and E profile s in the coatings. The changes of alpha -Al2O3 and gamma -Al2O3 contents re sult from the different cooling rates of the molten alumina in the microarc discharge channel at the different depths of the coatings. After the micro arc oxidation treatment, the microstructure of the alloy substrate, even ne ar the Al/Al2O3 interface, has not been changed. (C) 2001 Kluwer Academic P ublishers.