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Corrosion behaviour of a new Ti-6Al-2Nb-1Ta alloy in various solutions / C. Pirvu in Materials and corrosion, Vol. 62 N° 10 (Octobre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 10 (Octobre 2011) . - pp. 948–955 Titre : Corrosion behaviour of a new Ti-6Al-2Nb-1Ta alloy in various solutions Type de document : texte imprimé Auteurs : C. Pirvu, Auteur ; I. Demetrescu, Auteur ; P. Drob, Auteur Année de publication : 2012 Article en page(s) : pp. 948–955 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Corrosion  rates  EIS  Neutral  corrosive  environment  Pitting  corrosion  Titanium  alloy Résumé : A new Ti-6Al-2Nb-1Ta alloy was obtained for to satisfy the mechanical and anticorrosion requirements in neutral corrosive environment. The corrosion behaviour of this new Ti-6Al-2Nb-1Ta alloy in 0.1 M Na2SO4, 3% NaCl solutions and synthetic sea water was studied in this paper, using potentiodynamic and linear polarisation method, electrochemical impedance spectroscopy (EIS) and monitoring of the open circuit potentials. The structure of the alloy represents an α + β uniform structure with un-oriented grains. From the potentiodynamic polarisation curves it resulted that the studied alloy is self-passivated in all three solutions having a very good and very easy tendency to passivation. The most favourable values of the electrochemical parameters were registered in 0.1 M Na2SO4 solution due to its reduced corrosivity. EIS measurements proved the improvement of the passive layer resistance with the immersion time. An electric equivalent circuit with two time constants was fitted. The values of the polarisation resistances showed very good protective capacities which improved in time. The open circuit potentials have the general tendency to ennoble in time, suggesting the thickening of the passive films and the increase of their protective capacities. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201006041/abstract [article] Corrosion behaviour of a new Ti-6Al-2Nb-1Ta alloy in various solutions [texte imprimé] / C. Pirvu, Auteur ; I. Demetrescu, Auteur ; P. Drob, Auteur . - 2012 . - pp. 948–955. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 10 (Octobre 2011) . - pp. 948–955 Mots-clés : Corrosion  rates  EIS  Neutral  corrosive  environment  Pitting  corrosion  Titanium  alloy Résumé : A new Ti-6Al-2Nb-1Ta alloy was obtained for to satisfy the mechanical and anticorrosion requirements in neutral corrosive environment. The corrosion behaviour of this new Ti-6Al-2Nb-1Ta alloy in 0.1 M Na2SO4, 3% NaCl solutions and synthetic sea water was studied in this paper, using potentiodynamic and linear polarisation method, electrochemical impedance spectroscopy (EIS) and monitoring of the open circuit potentials. The structure of the alloy represents an α + β uniform structure with un-oriented grains. From the potentiodynamic polarisation curves it resulted that the studied alloy is self-passivated in all three solutions having a very good and very easy tendency to passivation. The most favourable values of the electrochemical parameters were registered in 0.1 M Na2SO4 solution due to its reduced corrosivity. EIS measurements proved the improvement of the passive layer resistance with the immersion time. An electric equivalent circuit with two time constants was fitted. The values of the polarisation resistances showed very good protective capacities which improved in time. The open circuit potentials have the general tendency to ennoble in time, suggesting the thickening of the passive films and the increase of their protective capacities. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201006041/abstract

Electrochemical stability and surface analysis in evaluation fluoride effect on new bioalloy Ti7Al3V2Mo2Fe used in dentistry / D. Ionita in Materials and corrosion, Vol. 62 N° 12 (Décembre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 12 (Décembre 2011) . - pp. 1111–1116 Titre : Electrochemical stability and surface analysis in evaluation fluoride effect on new bioalloy Ti7Al3V2Mo2Fe used in dentistry Type de document : texte imprimé Auteurs : D. Ionita, Auteur ; M. Prodana, Auteur ; I. Demetrescu, Auteur Année de publication : 2012 Article en page(s) : pp. 1111–1116 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Artificial  saliva  Fluoride  ions  Hydroxyapatite  Ti7Al3V2Mo2Fe  uncoated/coated Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The aim of this study is focused on the effect of fluoride concentration on the corrosion behavior of Ti7Al3V2Mo2Fe alloys uncoated/coated in artificial saliva. Ti7Al3V2Mo2Fe alloys were covered by chemical methods with hydroxyapatite to enhance the osteointegration of implants materials. The stability of Ti7Al3V2Mo2Fe alloys uncoated/coated in artificial saliva with/without fluoride ions was studied by electrochemical techniques (open circuit potential, cyclic voltammetry, and linear polarization). On the covered samples, dissolution test in simulated body fluids and wettability test were performed. Investigations regarding the sample surface modifications were made by atomic force microscopy and Fourier transform infrared spectroscopy. The results show that the corrosion resistance of Ti7Al3V2Mo2Fe in solution containing fluoride decreases in comparison with that in a solution not containing fluoride. Significant changes appear at a concentration larger than 0.05 M. The coating has a positive effect on corrosion resistance of metallic substrate in the fluoride presence acting as a semi-mechanical barrier. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005661/abstract [article] Electrochemical stability and surface analysis in evaluation fluoride effect on new bioalloy Ti7Al3V2Mo2Fe used in dentistry [texte imprimé] / D. Ionita, Auteur ; M. Prodana, Auteur ; I. Demetrescu, Auteur . - 2012 . - pp. 1111–1116. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 12 (Décembre 2011) . - pp. 1111–1116 Mots-clés : Artificial  saliva  Fluoride  ions  Hydroxyapatite  Ti7Al3V2Mo2Fe  uncoated/coated Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The aim of this study is focused on the effect of fluoride concentration on the corrosion behavior of Ti7Al3V2Mo2Fe alloys uncoated/coated in artificial saliva. Ti7Al3V2Mo2Fe alloys were covered by chemical methods with hydroxyapatite to enhance the osteointegration of implants materials. The stability of Ti7Al3V2Mo2Fe alloys uncoated/coated in artificial saliva with/without fluoride ions was studied by electrochemical techniques (open circuit potential, cyclic voltammetry, and linear polarization). On the covered samples, dissolution test in simulated body fluids and wettability test were performed. Investigations regarding the sample surface modifications were made by atomic force microscopy and Fourier transform infrared spectroscopy. The results show that the corrosion resistance of Ti7Al3V2Mo2Fe in solution containing fluoride decreases in comparison with that in a solution not containing fluoride. Significant changes appear at a concentration larger than 0.05 M. The coating has a positive effect on corrosion resistance of metallic substrate in the fluoride presence acting as a semi-mechanical barrier. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005661/abstract