Advertisement

Shape Memory and Superelasticity

, Volume 4, Issue 4, pp 417–427 | Cite as

The Effect of Low Temperature Aging and the Evolution of R-Phase in Ni-Rich NiTi

  • Ali Shamimi
  • Behnam Amin-Ahmadi
  • Aaron Stebner
  • Tom Duerig
Article
  • 80 Downloads

Abstract

This study investigates the thermal and mechanical properties that arise from aging Ni-rich Ni–Ti (Nitinol) at temperatures below 250 °C, well below those commonly used to fabricate medical devices. We demonstrate that the Ni50.8–Ti49.2 composition decomposes at temperatures as low as room temperature and discuss the unusual changes in thermal and mechanical behaviors compared to common aging treatments, such as separation of Martensite and R-phase transformations. Using such aging treatments, superelasticity can be achieved without the presence of austenite at body temperature (Af > 45 °C, well above the body temperature). Furthermore, the influence of R-phase on mechanical response and the disparity between thermal and mechanical behavior is discussed in detail.

Keywords

Aging R-phase Low temperature aging Mechanical properties Heat treatment NiTi < materials Precipitation 

References

  1. 1.
    Kim JI, Miyazaki S (2005) Effect of nano-scaled precipitates on shape memory behavior of Ti-50.9 at.% Ni alloy. Acta Mater 53:4545–4554CrossRefGoogle Scholar
  2. 2.
    Pourbabak S, Wang X, Van Dyck D, Verlinden B, Schryvers D (2017) Ni cluster formation in low temperature annealed Ni50.6Ti49.4. Funct Mater Lett 10(1):1740005CrossRefGoogle Scholar
  3. 3.
    Pérez-Sierra AM, Pons J, Santamarta R, Karaman I, Noebe RD (2016) Stability of a Ni-rich Ni-Ti-Zr high temperature shape memory alloy upon low temperature aging and thermal cycling. Scr Mater 124:47–50CrossRefGoogle Scholar
  4. 4.
    Duerig TW, Pelton AR, Bhattacharya K (2017) The measurement and interpretation of transformation temperatures in Nitinol. Shape Mem Superelast 3:485–498CrossRefGoogle Scholar
  5. 5.
    ASTM Designation: F 2004–16 (2000) Standard test method for transformation temperature of nickel–titanium alloys by thermal analysisGoogle Scholar
  6. 6.
    ASTM Designation: F 2516–14 (2006) Standard test method for tension testing of nickel–titanium superelastic materialsGoogle Scholar
  7. 7.
    Zheng Y, Jiang F, Li L, Yang H, Liu Y (2008) Effect of ageing treatment on the transformation behaviour of Ti–50.9 at.% Ni alloy. Acta Mater 56:736–745CrossRefGoogle Scholar
  8. 8.
    Zhou Z, Cui J, Ren X (2015) Strain glass state as the boundary of two phase transitions. Sci Rep 5:13377CrossRefGoogle Scholar
  9. 9.
    Khalil-Allafi J, Dlouhy A, Eggeler G (2002) Ni4Ti3-precipitation during aging of NiTi shape memory alloys and its influence on martensitic phase transformations. Acta Mater 50:4255–4274CrossRefGoogle Scholar
  10. 10.
    Reedlunn B, Churchill CB, Nelson EE, Shaw JA, Daly SH (2014) Tension, compression, and bending of superelastic shape memory alloy tubes. J Mech Phys Solids 63:506–537CrossRefGoogle Scholar
  11. 11.
    Feng P, Sun QP (2006) Experimental investigation on macroscopic domain formation and evolution in polycrystalline NiTi microtubing under mechanical force. J Mech Phys Solids 54:1568–1603CrossRefGoogle Scholar
  12. 12.
    Kustov S, Mas B, Salas D, Cesari E, Raufov S, Nikolaev V, Van Humbeeck J (2015) On the effect of room temperature ageing of Ni-rich Ni–Ti alloys. Scr Mater 103:10–13CrossRefGoogle Scholar
  13. 13.
    Kustov S, Mas B, Kuskarbaev Z, Wang X, Van Humbeeck J (2016) Reply to comment on: on the effect of room temperature ageing of Ni-rich Ni–Ti alloys. Scr Mater 123:166–168CrossRefGoogle Scholar

Copyright information

© ASM International 2018

Authors and Affiliations

  • Ali Shamimi
    • 1
  • Behnam Amin-Ahmadi
    • 2
  • Aaron Stebner
    • 2
  • Tom Duerig
    • 1
  1. 1.Confluent Medical Technologies Inc.FremontUSA
  2. 2.Colorado School of MinesGoldenUSA

Personalised recommendations