Effect of the anodization conditions on the growth and volume expansion of porous alumina films in malonic acid electrolyte

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F15%3APU117146" target="_blank" >RIV/00216305:26620/15:PU117146 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.surfcoat.2015.04.030" target="_blank" >http://dx.doi.org/10.1016/j.surfcoat.2015.04.030</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.surfcoat.2015.04.030" target="_blank" >10.1016/j.surfcoat.2015.04.030</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Effect of the anodization conditions on the growth and volume expansion of porous alumina films in malonic acid electrolyte

Popis výsledku v původním jazyce

Galvanostatic formation of nanoporous anodic films on aluminumwas performed in 0.6 M malonic acid electrolyte over a wide current density range in order to define the relationship between the anodizing behavior, oxide growth, dissolution and volume expansion of the oxide. The volume expansion and aluminum dissolution increase with raising the current density, the latter indicating an increasing potential difference across the electrolyte/barrier-layer interface. The same potential difference promotes dissociation of the acid molecules and incorporation of electrolyte-derived species into the film. The increase of volume expansion occurs in three phases, resulting fromthe two dissociation steps of malonic acid and from the change in the oxide growth mechanism at higher current densities. Infrared spectroscopy showed an enhanced presence of OH in films formed at higher current densities, indicating that lower coordination of aluminumaswell as anion incorporation contributes to volume expansion of the oxide. The current appeared to be 100% ionic in the interval of 5–100 mA cm-2, while being about 10% electronic beyond this range. At higher current densities a selflocalizing mechanism concentrates the ionic current to a smaller, spot-like area that moves continuously along the sample consuming steadily the whole metal thickness under the spot and thus forming a porous anodic film of highly self-ordered morphology, without physical imperfections. The volume expansion factor of the oxide becomes independent of the anodization current density under these conditions

Název v anglickém jazyce

Effect of the anodization conditions on the growth and volume expansion of porous alumina films in malonic acid electrolyte

Popis výsledku anglicky

Galvanostatic formation of nanoporous anodic films on aluminumwas performed in 0.6 M malonic acid electrolyte over a wide current density range in order to define the relationship between the anodizing behavior, oxide growth, dissolution and volume expansion of the oxide. The volume expansion and aluminum dissolution increase with raising the current density, the latter indicating an increasing potential difference across the electrolyte/barrier-layer interface. The same potential difference promotes dissociation of the acid molecules and incorporation of electrolyte-derived species into the film. The increase of volume expansion occurs in three phases, resulting fromthe two dissociation steps of malonic acid and from the change in the oxide growth mechanism at higher current densities. Infrared spectroscopy showed an enhanced presence of OH in films formed at higher current densities, indicating that lower coordination of aluminumaswell as anion incorporation contributes to volume expansion of the oxide. The current appeared to be 100% ionic in the interval of 5–100 mA cm-2, while being about 10% electronic beyond this range. At higher current densities a selflocalizing mechanism concentrates the ionic current to a smaller, spot-like area that moves continuously along the sample consuming steadily the whole metal thickness under the spot and thus forming a porous anodic film of highly self-ordered morphology, without physical imperfections. The volume expansion factor of the oxide becomes independent of the anodization current density under these conditions

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10405 - Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)

Projekt

<a href="/cs/project/GA14-29531S" target="_blank" >GA14-29531S: Vytváření a vlastnosti vrstev z nových samouspořádaných 3D nanostruktur ze smíšených oxidů pro využití v pokročilých mikrosoučástkách (AnoNanoFilm)</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2015

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Surface and Coatings Technology

ISSN

0257-8972

e-ISSN

—

Svazek periodika

275

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

8

Strana od-do

18-25

Kód UT WoS článku

000357753900004

EID výsledku v databázi Scopus

2-s2.0-84930863806