Nanostructure effect on the electrochemical response of titanium
Agata Sotniczuk , Marta Zwolińska , Maria Sozańska , Andrzej Królikowski , Halina Garbacz
AbstractThe purpose of this work was to investigate the influence of nanostructure on titanium corrosion resistance in physiological saline (0.9% NaCl). In order to obtain the nanostructure the titanium rod was processed through multiple hydrostatic extrusion (HE). Corrosion tests included electrochemical impedance (EIS) and potentiodynamic (PD) measurements. EIS tests were performed after 2 and 24 hours of immersion in 0.9% NaCl. Potentiodynamic measurements were carried out immediately after the last impedance test. Profilometric examination was used to check whether the samples were equally prepared for corrosion measurements. After corrosion tests a scanning electron microscope (SEM) was used to characterize the morphology of the surface. Corrosion tests revealed the positive influence of nanostructure on titanium corrosion resistance. Moreover, the differences observed were larger in the case of a shorter time of immersion in physiological saline. Hence, it might be surmised that the rate of the passivation process depends on titanium grain size. The microscopic characterization of the surfaces of samples after the corrosion test indicated differences in the surface morphology. The passive film formed on the nanocrystalline sample was more compact and homogenous than on the microcrystalline one. The different number of structural defects in micro- and nanocrystalline titanium might be the reason for the observed phenomena. Due to their higher energy, structural defects could be preferential sites for the nucleation of passive layers. Consequently, the rate of passivation should be higher for nanocrystalline materials. Furthermore, the high volume fraction of structural defects also explained the existence of more tight and uniform passive layer on the nanocrystalline titanium. Good corrosion resistance in physiological saline means that nanotitanium could be an attractive material for biomedical applications.
|Journal series||Inżynieria Materiałowa, ISSN 0208-6247|
|Publication size in sheets||0.5|
|Keywords in Polish||Korozja, nanokrystaliczny tytan, aplikacje biomedyczne|
|Keywords in English||corrosion, nanostructured titanium, biomedical application|
|Score|| = 13.0, 28-11-2017, ArticleFromJournal|
= 13.0, 28-11-2017, ArticleFromJournal
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