Premium
New oxidation treatment of NiTi shape memory alloys to obtain Ni‐free surfaces and to improve biocompatibility
Author(s) -
Michiardi A.,
Aparicio C.,
Planell J.A.,
Gil F.J.
Publication year - 2006
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.30441
Subject(s) - shape memory alloy , biocompatibility , x ray photoelectron spectroscopy , nickel titanium , materials science , oxide , corrosion , metallurgy , chemical engineering , differential scanning calorimetry , oxygen , chemistry , organic chemistry , physics , engineering , thermodynamics
Various oxidation treatments were applied to nearly equiatomic NiTi alloys so as to form a Ni‐free protective oxide on the surface. Sample surfaces were analyzed by X‐ray Photoelectron Spectroscopy, and NiTi transformation temperatures were determined by differential scanning calorimetry (DSC) before and after the surface treatment. An ion release experiment was carried out up to one month of immersion in SBF for both oxidized and untreated surfaces. The results show that oxidation treatment in a low‐oxygen pressure atmosphere leads to a high surface Ti/Ni ratio, a very low Ni surface concentration and a thick oxide layer. This oxidation treatment does not significantly affect the shape memory properties of the alloy. Moreover, the oxide formed significantly decreases Ni release into exterior medium comparing with untreated surfaces. As a consequence, this new oxidation treatment could be of great interest for biomedical applications, as it could minimize sensitization and allergies and improve biocompatibility and corrosion resistance of NiTi shape memory alloys. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006