Influence of Microstructure on the Performance of Nitinol: A Computational Analysis

• DOI: 10.1007/s11665-014-1017-5
• Publication Date: 2014-04-25T17:03:11Z
• Authors: F. M. Weafer; M. S. Bruzzi
• Keywords: Nickel titanium; Texture (cosmology); Pseudoelasticity; Volume fraction

One material that has found particular favor for use in biomedical endovascular stents is the near equi-atomic NiTi alloy, Nitinol. remarkable trait exhibited by this superelastic improvement of its fatigue performance with increasing mean strain (Ref 1, 2). Clarification into phenomenon still remains incomplete literature. This study proposes a microstructural explanation unique macroscopic behavior; it hypothesized stress-induced martensite (SIM) will stabilize which, turn, leads to observed increase life. Finite element analysis (FEA) employed investigate behavior "v-strut" stent subcomponent under various levels. The volume fraction SIM analyzed identify potential influence on response and, ultimately, behavior. In addition, computational investigation performed effect crystallographic texture response. Granular transformational using FEA models realistic and idealized grain structures, specifically evaluating individual orientations transformation.