| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 672916 | Thermochimica Acta | 2015 | 6 Pages |
•Applying aging and thermomechanical treatments change the features of DSC curves.•Optimum aging temperatures for reaching very good superelasticity was determined.•Applying cold work before aging treatment improved the superelastic behavior of the alloy.•Highly Ni-rich Ti-51.5 at.% Ni NiTi alloy can exhibit excellent superelasticity.
This paper evaluates influences of aging and thermomechanical treatments on the martensitic transformation and superelasticity of a highly Ni-rich Ti-51.5 at.% Ni. For this purpose, the alloy was subjected to aging and thermomechanical treatments. One group of sample was aged for 1 h at 300–700 °C with 100 °C intervals. The other group firstly was cold rolled to a reduction of 20% and then aged for 1 h at the previous temperature range. Results showed that solution annealed and aged samples at 700 °C showed no superelasticity because of high nickel content in the matrix of the alloy. For the aged samples, complete superelasticity was observed by aging at 400 and 500 °C. Applying 20% cold rolling before aging led to increase aging temperature for observing good superelastic behavior. Compared to the aged samples at 300 and 600 °C, for cold worked and aged samples at 300 and 600 °C, recovered strain after unloading at 5% strain, was increased 0.8 and 0.7%, respectively.
