Study on the kinetics of growth of porous anodic Al2O3 films on Al metal

Patermarakis, G; Papandreadis, N

dc.contributor.author	Patermarakis, G	en
dc.contributor.author	Papandreadis, N	en
dc.date.accessioned	2014-03-01T01:09:34Z
dc.date.available	2014-03-01T01:09:34Z
dc.date.issued	1993	en
dc.identifier.issn	0013-4686	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/11083
dc.subject	aluminium	en
dc.subject	anodizing	en
dc.subject	growth	en
dc.subject	kinetics	en
dc.subject	oxide	en
dc.subject	porous	en
dc.subject.classification	Electrochemistry	en
dc.subject.other	ALUMINUM	en
dc.title	Study on the kinetics of growth of porous anodic Al2O3 films on Al metal	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/0013-4686(93)80119-K	en
heal.identifier.secondary	http://dx.doi.org/10.1016/0013-4686(93)80119-K	en
heal.language	English	en
heal.publicationDate	1993	en
heal.abstract	A kinetic study on the growth of porous anodic Al2O3 films on Al metal, anodized galvanostatically at current densities 5-75 mA cm-2 in a stirred 15% w/v H2SO4 bath solution at bath temperatures 20-40°C, was performed. A strict kinetic model was formulated which was, nevertheless, rather complex. Thereafter, a simplified model was derived from the former on the basis of certain assumptions. The latter was found to apply satisfactorily to the experimental values of film mass at all bath temperatures and current densities employed. The model's application is valid approximately up to the anodization time at which maximum pore diameter approaches cell size. Treatment of results with this model yielded a satisfactory estimation of the parameters involved in the kinetics governing the thermally activated dissolution process effected by the electrolyte on either the pore wall oxide during anodization or on the oxide in an open circuit. It was verified that electrolyte concentration inside pores during anodization varies along the pore length, increasing in the direction from the film's surface down to the pore bases. At pore bases, the electrolyte concentration generally increases with decreasing bath temperature and increasing current density, being approximately a linear function of true current density at the corresponding surface of charge exchange. In addition, it was shown that a sufficiently accurate determination of structural features is possible to be obtained. A feature examined and being of specific interest is the real shape of pores which for stirred-bath films assumes that of an elongated spinning top. © 1993.	en
heal.publisher	PERGAMON-ELSEVIER SCIENCE LTD	en
heal.journalName	Electrochimica Acta	en
dc.identifier.doi	10.1016/0013-4686(93)80119-K	en
dc.identifier.isi	ISI:A1993MA41000029	en
dc.identifier.volume	38	en
dc.identifier.issue	15	en
dc.identifier.spage	2351	en
dc.identifier.epage	2361	en