Polymer-filled Superelastic Thin Film NiTi Tubes

Eckhard Quandt 1Holger Rumpf 1Christiane Zamponi 1Christoph Bourauel 3Dieter Drescher 2Nikolai Botkin 1

1. center of advanced european studies and research (caesar), Ludwig-Erhard-Allee 2, Bonn 53175, Germany
2. University of Duesseldorf, Polyclinic for Orthodontics, Düsseldorf 40225, Germany
3. University of Bonn, Polyclinic for Orthodontics, Bonn 53117, Germany

Abstract

Superelastic shape memory materials are of special interest in medical applications due to the large obtainable strains, the constant stress level and their biocompatibility. Superelastic NiTi-polymer-composites have the potential to be used for novel applications in orthodontics and medical instrumentation as well as in certain areas of mechanical engineering. Especially, using NiTi thin films these composites have the potential to substantially reduce those forces compared to conventional NiTi wires and tubes. In orthodontic applications lowering the forces during archwire treatment is of special importance due to the risk of root resorption, which can be caused by the application of excessive forces. Furthermore, the use of superelastic materials or composites enables the application of constant forces independent of tooth movements during the therapy due to the superelastic plateau. Superelastic NiTi thin films have been fabricated by magnetron sputtering using extremely pure cast melted targets. Special heat treatments were performed for the adjustment of the superelastic properties and the transformation temperatures. A superelastic strain exceeding 6.5% at 400 MPa was obtained. In this paper the fabrication of superelastic NiTi thin walled tubes by magnetron sputtering their structural and thermomechanical properties are presented. Bending test results are compared to conventional wires in view of orthodontic applications.


Financial support of the German Federal Ministry of Education and Research (BMBF, Contract 03N4031A) is gratefully acknowledged.

 

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Presentation: invited oral at E-MRS Fall Meeting 2005, Symposium C, by Eckhard Quandt
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-05-30 11:16
Revised:   2009-06-07 00:44