Transformation temperature changes due to second phase precipitation in NiTi-based shape memory alloys
Source abstract
Abstract
This study investigated changes in the martensite start temperature ( M s ) of NiTi-based shape memory alloys as a result of second phase precipitation. Precipitation of the second phase leads to a change in the matrix chemical composition and may alter the electron concentration ( c v) of the matrix. When the electron concentration of the matrix increases, the transformation temperature decreases, whereas the M s temperature rises when the c v of the matrix decreases. Additionally, if the precipitation does not result in a significant variation of the c v of the matrix, the variation in M s is small (<15 °C). In the present work it is shown that alteration of the M s temperature as a result of precipitation is mainly due to the change in electron concentration of the matrix. The extrinsic effect of the precipitates on M s is also discussed on the basis of their quantities in the as-quenched and aged microstructures and the strain energy induced in the matrix.
Source: expertdata · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Shape Memory Alloy Transformations
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (33)
Show source-provided references
1. Otsuka · 1998
2. The physical metallurgy of Ti–Ni-based shape memory alloys10.1016/j.pmatsci.2004.10.001 ↗
3. Martensitic transformation of Cu-based shaped-memory alloys: elastic anisotropy and entropy change10.1103/PhysRevB.45.7633 ↗
4. Elastic constants of BCC Cu–Al–Ni alloys10.1103/PhysRevB.49.9969 ↗
5. A comparative study of elastic constants of Ti–Ni based alloys prior to martensitic transformation10.1016/S0921-5093(00)01876-1 ↗
6. A localized soft mode theory for martensitic transformations10.1002/pssb.2220570213 ↗
7. Pre-transformation effects of localized soft modes on neutron scattering, acoustic attenuation, and Mössbauer resonance measurements10.1007/BF02649733 ↗
8. Dependence of the transformation temperatures of NiTi-based shape memory alloys on the number and concentration of valence electrons10.1002/adfm.200701423 ↗
9. Zarinejad M, Liu Y. Dependence of the transformation temperatures of shape memory alloys on the number and concentration of valence electrons. In: Chen HR, editor. Shape memory alloys: manufacture, properties and applications. New York: Nova Science Publishers; 2009. submitted for publication.10.1002/adfm.200701423 ↗
10. Gilman · 2003
11. Design of hard crystals10.1016/j.ijrmhm.2005.05.015 ↗
12. Characterization of ternary NiTiPt high-temperature shape memory alloys, smart structures and materials
13. Aging effect on a Ti47.25Ni48.75V4 shape memory alloy10.1016/j.jallcom.2006.01.136 ↗
14. A study on ternary Ti-rich TiNiZr shape memory alloys10.1016/S1044-5803(98)00032-1 ↗
15. Effect of precipitation on the shape memory effect of Ti50Ni25Cu25 melt-spun ribbon10.1016/j.actamat.2007.12.031 ↗
16. Martensitic transformation of a Ti-rich Ti40.5Ni49.5Zr10 shape memory alloy10.1016/S0925-8388(99)00604-0 ↗
17. Tong YX. Ph.D. thesis, Nanyang Technological University, Singapore; 2008.
18. Effect of aging on the phase transformation and mechanical behavior of Ti36Ni49Hf15 high temperature shape memory alloy10.1016/S1359-6462(99)00347-4 ↗
19. Formation of TiCu plate-like precipitates in Ti50Ni25Cu25 shape memory alloys10.1016/S1359-6462(00)00541-8 ↗
20. The martensitic transformation in Ti-rich TiNi shape memory alloys10.1016/0254-0584(94)90091-4 ↗
21. Quantitative phase analysis in microstructures which display multiple step martensitic transformations in Ni-rich NiTi shape memory alloys10.1016/j.msea.2006.02.143 ↗
22. Origin of abnormal multi-stage martensitic transformation behavior in aged Ni-rich Ti–Ni shape memory alloys10.1016/j.actamat.2004.06.002 ↗
23. Martensitic transformations and functional properties of thermally and thermomechanically treated Ti–Ni–Nb-based alloys10.1016/j.msea.2006.05.170 ↗
24. Effect of ageing on transformation kinetics and internal friction of Ni-rich Ni–Ti alloys10.1016/j.jallcom.2007.05.102 ↗
25. The influence of aging on critical transformation stress levels and martensite start temperatures in NiTi: part I – aged microstructure and micro-mechanical modeling
26. The influence of coherent and semi-coherent TiCu precipitates on the martensitic transformation of melt-spun Ti50Ni25Cu25 shape memory ribbons10.2320/matertrans.42.1758 ↗
27. Shape memory behaviors in an age Ni-rich TiNiHf high temperature shape memory alloy10.1016/j.intermet.2008.02.005 ↗
28. A new precipitate phase in a TiNiHf high temperature shape memory alloy10.1016/S1359-6454(97)00187-0 ↗
29. Structure and substructure of martensite in a Ti36.5Ni48.5Hf15 high temperature shape memory alloy10.1016/1359-6454(96)00034-1 ↗
30. Improvement of shape memory characteristics by precipitation-hardening of Ti–Pd–Ni alloys10.1016/S0167-577X(97)00134-1 ↗
31. Microstructure and shape memory behavior of Ti51.2(Pd27.0Ni21.8) and Ti49.5(Pd28.5Ni22.0) thin films10.1016/S0921-5093(01)01714-2 ↗
32. Characterisation of phase transformation inTi50+xPd30Ni20−x alloys10.1016/S0966-9795(02)00048-1 ↗
33. The crystal chemistry of NiTiHf shape memory alloys10.1016/j.intermet.2008.04.004 ↗