E. Delvecchio, A. Ferretto, S. Polizu, L. '. Yahia, Ecole Polytechnique of Montreal, Montreal, QC, Canada; B. Terrault, University of Quebec, Varennes, QC, Canada
The use of Nitinol in medical device applications has expanded significantly in the last 20 years. Since the surface chemical and morphological properties control the interactions with the biological environment, for Nitinol alloys it is very desirable to carry on shape memory and pseudoelastic behaviour in the bulk material, while maintaining a highly biocompatible surface with exceptional wear and corrosion resistance. The plasma ion implantation technique is able to create a continuous interface between the surface and the bulk, without altering its mechanical properties. Therefore, it is possible to induce a nickel depletion of the NiTi surface and to form a biocompatible nickel free surface using this non-light of sight method.
The aim of this work is to apply the oxygen ion implantation technique on Nitinol alloy in order to optimize the ion implantation process parameters and to obtain the best long term biocompatibility and wear and corrosion resistance of the material.
Using high performance surface analyse techniques (XPS, LV-SEM, EDS as well as Contact Angle) we evaluate the chemical and morphological properties of the modified alloy. Therefore, we intend to define the optimal ion dose and to establish the relationship between the processing parameters and the surface characteristics. The role of annealing treatment will also be considered.
Summary: The use of Nitinol in medical device applications has expanded significantly in the last 20 years. Since the surface chemical and morphological properties control the interactions with the biological environment, for Nitinol alloys it is very desirable to carry on shape memory and pseudoelastic behaviour in the bulk material, while maintaining a highly biocompatible surface with exceptional wear and corrosion resistance. The plasma ion implantation technique is able to create a continuous interface between the surface and the bulk, without altering its mechanical properties. Therefore, it is possible to induce a nickel depletion of the NiTi surface and to form a biocompatible nickel free surface using this non-light of sight method.
The aim of this work is to apply the oxygen ion implantation technique on Nitinol alloy in order to optimize the ion implantation process parameters and to obtain the best long term biocompatibility and wear and corrosion resistance of the material.
Using high performance surface analyse techniques (XPS, LV-SEM, EDS as well as Contact Angle) we evaluate the chemical and morphological properties of the modified alloy. Therefore, we intend to define the optimal ion dose and to establish the relationship between the processing parameters and the surface characteristics. The role of annealing treatment will also be considered.
