Cycling behaviour and temperature memory effect in Ni-35Ti-15Hf high temperature shape memory alloys
Year: 2026
Type: article
Abstract: New high-temperature shape memory alloys (HTSMA) based on the system Ni-Ti-Hf are being developed to exhibit the martensitic transformation (MT) between 100 and 300ºC, to work in many technological applications operating in such temperature range, which is forbidden for the classical NiTi based SMA. To fulfil the requirements of such applications, the thermal behaviour of the alloy must be thermally stable on cycling. This must include the behaviour in real scenarios where the thermal cycles of the functional SMA component may fluctuate producing a partial or incomplete MT. In this case a problem may arise because SMA exhibit a phenomenon called “temperature memory effect” (TME), which occurs when the reverse MT is interrupted producing a stabilization of the martensite and modifying the thermal response of the SMA. In the present work, the characterization of the TME in a HTSMA of Ni-35Ti-15Hf (at.%) is approached through differential scanning calorimetry. The results show deviations above 10ºC associated with the TME, which are quantified as a function of the number of partial cycles, and a functional model is proposed. In contrast with previously reported works in other SMA, our results show that in the case of NiTiHf the TME let a residual mark, which is also quantified. The possibility of resetting the original behaviour is analysed, offering the experimental methodology. Finally, the results are explained on the base of conceptual models, analysing the potential influence of the TME on real applications of HTSMA.
Source: Journal of Alloys and Compounds
Institution: University of the Basque Country
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,660
OpenAlex ID: W7214119129