Details
| Original language | English |
|---|---|
| Pages (from-to) | 257-267 |
| Number of pages | 11 |
| Journal | Acta biomaterialia |
| Volume | 5 |
| Issue number | 1 |
| Publication status | Published - Jan 2009 |
| Externally published | Yes |
Abstract
The objective of this work is to understand the structure-property relationships in polycrystalline NiTiPt (Ti 42.7 at.% Ni 7.5 at %Pt) with a composition showing pseudoelasticity at ambient temperatures. Structural characterization of the alloy includes grain size determination and texture analysis while the thermomechanical properties are explored using tensile testing. Variation in heat treatment is used as a vehicle to modify microstructure. The results are compared to experiments on Ni-rich NiTi alloy wires (Ti-51.0 at.% Ni), which are in commercial use in various biomedical applications. With regards to microstructure, both alloys exhibit a <1 1 1> fiber texture along the wire drawing axis; however, the NiTiPt alloy grain size is smaller than that of the Ni-rich NiTi wires, while the latter materials contain second-phase precipitates. Given the nanometer-scale grain size in NiTiPt and the dispersed, nanometer-scale precipitate size in NiTi, the overall strength and ductility of the alloys are essentially identical when given appropriate heat treatments. Property differences include a much smaller stress hysteresis and smaller temperature dependence of the transformation stress for NiTiPt alloys compared to NiTi alloys. Potential benefits and implications for use in vascular stent applications are discussed.
Keywords
- Nitinol, Platinum, Shape memory alloys, TEM, Thermomechanical properties
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Biotechnology
- Materials Science(all)
- Biomaterials
- Biochemistry, Genetics and Molecular Biology(all)
- Biochemistry
- Engineering(all)
- Biomedical Engineering
- Biochemistry, Genetics and Molecular Biology(all)
- Molecular Biology
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In: Acta biomaterialia, Vol. 5, No. 1, 01.2009, p. 257-267.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Structure and thermomechanical behavior of NiTiPt shape memory alloy wires
AU - Lin, Brian
AU - Gall, Ken
AU - Maier, Hans J.
AU - Waldron, Robbie
PY - 2009/1
Y1 - 2009/1
N2 - The objective of this work is to understand the structure-property relationships in polycrystalline NiTiPt (Ti 42.7 at.% Ni 7.5 at %Pt) with a composition showing pseudoelasticity at ambient temperatures. Structural characterization of the alloy includes grain size determination and texture analysis while the thermomechanical properties are explored using tensile testing. Variation in heat treatment is used as a vehicle to modify microstructure. The results are compared to experiments on Ni-rich NiTi alloy wires (Ti-51.0 at.% Ni), which are in commercial use in various biomedical applications. With regards to microstructure, both alloys exhibit a <1 1 1> fiber texture along the wire drawing axis; however, the NiTiPt alloy grain size is smaller than that of the Ni-rich NiTi wires, while the latter materials contain second-phase precipitates. Given the nanometer-scale grain size in NiTiPt and the dispersed, nanometer-scale precipitate size in NiTi, the overall strength and ductility of the alloys are essentially identical when given appropriate heat treatments. Property differences include a much smaller stress hysteresis and smaller temperature dependence of the transformation stress for NiTiPt alloys compared to NiTi alloys. Potential benefits and implications for use in vascular stent applications are discussed.
AB - The objective of this work is to understand the structure-property relationships in polycrystalline NiTiPt (Ti 42.7 at.% Ni 7.5 at %Pt) with a composition showing pseudoelasticity at ambient temperatures. Structural characterization of the alloy includes grain size determination and texture analysis while the thermomechanical properties are explored using tensile testing. Variation in heat treatment is used as a vehicle to modify microstructure. The results are compared to experiments on Ni-rich NiTi alloy wires (Ti-51.0 at.% Ni), which are in commercial use in various biomedical applications. With regards to microstructure, both alloys exhibit a <1 1 1> fiber texture along the wire drawing axis; however, the NiTiPt alloy grain size is smaller than that of the Ni-rich NiTi wires, while the latter materials contain second-phase precipitates. Given the nanometer-scale grain size in NiTiPt and the dispersed, nanometer-scale precipitate size in NiTi, the overall strength and ductility of the alloys are essentially identical when given appropriate heat treatments. Property differences include a much smaller stress hysteresis and smaller temperature dependence of the transformation stress for NiTiPt alloys compared to NiTi alloys. Potential benefits and implications for use in vascular stent applications are discussed.
KW - Nitinol
KW - Platinum
KW - Shape memory alloys
KW - TEM
KW - Thermomechanical properties
UR - http://www.scopus.com/inward/record.url?scp=56349124137&partnerID=8YFLogxK
U2 - 10.1016/j.actbio.2008.07.015
DO - 10.1016/j.actbio.2008.07.015
M3 - Article
C2 - 18718825
AN - SCOPUS:56349124137
VL - 5
SP - 257
EP - 267
JO - Acta biomaterialia
JF - Acta biomaterialia
SN - 1742-7061
IS - 1
ER -