ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The kinetics of film-forming process of anodizing on AZ91D Mg alloy have been studiedthrough analyses of voltage-time and thickness–time curves. The surface morphology, structure,composition and valence of element, phase constituent of anodic films have been analyzed by SEM,EDS, XPS and XRD respectively. The results show that the film-forming process can be divided intofour stages: I - formation of a dense layer; II - formation of a porous layer; III - fast growth of theporous layer; IV - slow growth of the porous layer. The growing process of the dense film ischaracterized by the rapidly formed intact and imperforate oxide film; there are few micro-cracks inpartial film formed on α phase, on the contrary, intact film is formed on β phase; the forming ofporous film is based on the particulate sparking product with micro-porous structure. There are twokinds of pores in the anodic film; the first one is circular or ellipse, while the second one is theirregular gaps. The dense layer is composed mainly of MgO and small amount of Al2O3, while theporous layer mainly consists of MgSiO3 and Mg3B2O6. We propose a possible model about growinganodizing film on AZ91D Mg alloy based on the experimental results
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/16/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.546-549.589.pdf
Permalink