Development of Biomimetic NiTi Alloy: Influence of Thermo-Chemical Treatment on the Physical, Mechanical and Biological Behavior

• Published in: Materials Vol. 9; no. 6; p. 402
• Main Authors: Rupérez, Elisa, Manero, José María, Bravo-González, Luis-Alberto, Espinar, Eduardo, Gil, F J
• Format: Journal Article Publication
• Language: English
• Published: Switzerland MDPI AG 24.05.2016; MDPI
• Subjects: Aliatges; Alloys; Aqueous solutions; Assaig de materials; Assaigs de materials; Bioactivity; Biological activity; Biomimetic materials; Biomimetic surfaces; Biomimètica; Calcium phosphates; Elasticitat; Elasticity; Enginyeria dels materials; Intermetallic compounds; Intermetallics; Materials; Nickel; Nickel base alloys; Nickel compounds; Nickel titanides; Nickel-titanium alloys; NiTi alloy; Níquel; Oxidation; Shape memory alloys; Shape memory effect; Superelasticity; Surgical implants; Testing; Titani; Titanium; Titanium compounds; Toxicity; Transplants & implants; Àrees temàtiques de la UPC; Spain; biomimetic surfaces; superelasticity; bioactivity; NiTi alloy; shape memory effect
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma9060402

A bioactive layer, free of nickel, has been performed for its greater acceptability and reliability in clinical applications for NiTi shape memory alloys. In the first step, a safe barrier against Ni release has been produced on the surface by means of a thicker rutile/anastase protective layer free of nickel. In the second step, a sodium alkaline titanate hydrogel, which has the ability to induce apatite formation, has been performed from oxidized surface. An improvement of host tissue-implant integration has been achieved in terms of Ni ions release and the bioactivity of the treated NiTi alloys has been corroborated with both and studies. The transformation temperatures (A , A , M , and M ), as well as the critical stresses (σ ), have been slightly changed due to this surface modification. Consequently, this fact must be taken into account in order to design new surface modification on NiTi implants.