| Titre : | The influence of secondary phase carbide particles on the passivity behaviour of NiTi shape memory alloys (2014) |
| Auteurs : | L. Neelakantan, Auteur ; B. Monchev, Auteur ; M. Frotscher, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Materials and corrosion (Vol. 63 N° 11, Novembre 2012) |
| Article en page(s) : | pp. 979–984 |
| Note générale : | Génie mécanique |
| Langues : | Anglais |
| Tags : | Inclusions ; interfaces ; nickel titanium shape memory alloys ; pitting ; polarisation |
| Résumé : | The current investigation aims at studying the passivity behaviour of NiTi shape memory alloys with different levels of secondary phase titanium carbide (TiC) particles in an electrolyte of 0.9% sodium chloride at 37 °C. The influence of carbides and thermo-mechanical treatment/cold working on the passivity breakdown is highlighted. The polarisation studies on the as-cast and cold worked NiTi with high (0.05 wt%) and low (0.005 wt%) carbon levels show a significant difference in oxide stability. The alloy with extremely low carbon content shows a higher breakdown potential. Higher carbon levels result in higher density of larger TiC and these carbide/matrix interfaces are more susceptible to pitting. The qualitative behaviour of passive layer formed at 0.5 V on the cold worked NiTi alloy with different carbon levels was ascertained by electrochemical impedance spectroscopy (EIS). The oxide on the NiTi alloy with high (0.05 wt%) carbon levels showed lower resistance and poor stability at this condition. |
| En ligne : | http://onlinelibrary.wiley.com/doi/10.1002/maco.201106402/abstract |
