Hydrogen Effect on the Cyclic Behavior of a Superelastic NiTi Archwire
In this work, we are interested in examining the strain rate effect on the mechanical behavior of Ni–Ti superelastic wires after hydrogen charging and ageing for 24 h. Specimens underwent 50 cycles of loading-unloading, reaching an imposed deformation of 7.6%. During loading, strain rates...
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MDPI AG
2019-03-01
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| Series: | Metals |
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| Online Access: | http://www.mdpi.com/2075-4701/9/3/316 |
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| author | Rihem Sarraj Amir Kessentini Tarek Hassine Ali Algahtani Fehmi Gamaoun |
| author_facet | Rihem Sarraj Amir Kessentini Tarek Hassine Ali Algahtani Fehmi Gamaoun |
| author_sort | Rihem Sarraj |
| collection | DOAJ |
| description | In this work, we are interested in examining the strain rate effect on the mechanical behavior of Ni–Ti superelastic wires after hydrogen charging and ageing for 24 h. Specimens underwent 50 cycles of loading-unloading, reaching an imposed deformation of 7.6%. During loading, strain rates from 10−4 s−1 to 10−2 s−1 were achieved. With a strain rate of 10−2 s−1, the specimens were charged by hydrogen for 6 h and aged for one day showed a superelastic behavior marked by an increase in the residual deformation as a function of the number of cycles. In contrast, after a few number of cycles with a strain rate of 10−4 s−1, the Ni-Ti alloy archwire specimens fractured in a brittle manner during the martensite transformation stage. The thermal desorption analysis showed that, for immersed specimens, the desorption peak of hydrogen appeared at 320 °C. However, after annealing the charged specimens by hydrogen at 400 °C for 1 h, an embrittlement took place at the last cycles for the lower strain rates of 10−4 s−1. The present study suggests that the embrittlement can be due to the development of an internal stress in the subsurface of the parent phase during hydrogen charging and due to the creation of cracks and local zones of plasticity after desorption. |
| first_indexed | 2024-12-22T07:30:38Z |
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| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-12-22T07:30:38Z |
| publishDate | 2019-03-01 |
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| spelling | doaj.art-c3b980c9a5084fa0985fbdf3916ac6ae2022-12-21T18:34:02ZengMDPI AGMetals2075-47012019-03-019331610.3390/met9030316met9030316Hydrogen Effect on the Cyclic Behavior of a Superelastic NiTi ArchwireRihem Sarraj0Amir Kessentini1Tarek Hassine2Ali Algahtani3Fehmi Gamaoun4Laboratory of Mechanics of Sousse, National Engineering School of Sousse, University of Sousse, Sousse 4054, TunisiaDepartment of Mechanical Engineering, College of Engineering, King Khalid University, Abha 61421, Saudi ArabiaLaboratory of Mechanics of Sousse, National Engineering School of Sousse, University of Sousse, Sousse 4054, TunisiaDepartment of Mechanical Engineering, College of Engineering, King Khalid University, Abha 61421, Saudi ArabiaDepartment of Mechanical Engineering, College of Engineering, King Khalid University, Abha 61421, Saudi ArabiaIn this work, we are interested in examining the strain rate effect on the mechanical behavior of Ni–Ti superelastic wires after hydrogen charging and ageing for 24 h. Specimens underwent 50 cycles of loading-unloading, reaching an imposed deformation of 7.6%. During loading, strain rates from 10−4 s−1 to 10−2 s−1 were achieved. With a strain rate of 10−2 s−1, the specimens were charged by hydrogen for 6 h and aged for one day showed a superelastic behavior marked by an increase in the residual deformation as a function of the number of cycles. In contrast, after a few number of cycles with a strain rate of 10−4 s−1, the Ni-Ti alloy archwire specimens fractured in a brittle manner during the martensite transformation stage. The thermal desorption analysis showed that, for immersed specimens, the desorption peak of hydrogen appeared at 320 °C. However, after annealing the charged specimens by hydrogen at 400 °C for 1 h, an embrittlement took place at the last cycles for the lower strain rates of 10−4 s−1. The present study suggests that the embrittlement can be due to the development of an internal stress in the subsurface of the parent phase during hydrogen charging and due to the creation of cracks and local zones of plasticity after desorption.http://www.mdpi.com/2075-4701/9/3/316hydrogenNiTi alloyssuperelasticmartensitecyclic effect |
| spellingShingle | Rihem Sarraj Amir Kessentini Tarek Hassine Ali Algahtani Fehmi Gamaoun Hydrogen Effect on the Cyclic Behavior of a Superelastic NiTi Archwire Metals hydrogen NiTi alloys superelastic martensite cyclic effect |
| title | Hydrogen Effect on the Cyclic Behavior of a Superelastic NiTi Archwire |
| title_full | Hydrogen Effect on the Cyclic Behavior of a Superelastic NiTi Archwire |
| title_fullStr | Hydrogen Effect on the Cyclic Behavior of a Superelastic NiTi Archwire |
| title_full_unstemmed | Hydrogen Effect on the Cyclic Behavior of a Superelastic NiTi Archwire |
| title_short | Hydrogen Effect on the Cyclic Behavior of a Superelastic NiTi Archwire |
| title_sort | hydrogen effect on the cyclic behavior of a superelastic niti archwire |
| topic | hydrogen NiTi alloys superelastic martensite cyclic effect |
| url | http://www.mdpi.com/2075-4701/9/3/316 |
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