Thin-walled Ni-Ti tubes under compression : ideal candidates for efficient and fatigue-resistant elastocaloric cooling

Porenta, Luka (avtor), Kabirifar, Parham (avtor), Žerovnik, Andrej (avtor), Čebron, Matjaž (avtor), Žužek, Borut (avtor), Dolenec, Matej (avtor), Brojan, Miha (avtor), Tušek, Jaka (avtor)

Elastocaloric cooling is emerging as one of the most promising alternatives to vapor-compression cooling technology. It is based on the elastocaloric effect (eCE) of shape memory alloys (SMAs), which occurs due to a stress-induced martensitic transformation (superelasticity). In recent years, several elastocaloric proof-of-concept devices have been developed and the best of them have already achieved commercially relevant cooling characteristics. However, the proposed devices are not yet ready for commercialization, mostly due to their short fatigue life, which is a consequence of the tensile loading. The fatigue life can be significantly improved if the material is instead subjected to compressive loading, but mechanical instabilities (buckling) and the poor heat transfer of bulky geometries (favorable for compression) are the major challenges to overcome when designing compressed elastocaloric elements. Here, we show for the first time that thin-walled Ni-Ti tubes, which allow for the rapid heat transfer, can withstand more than 10$^6$ compressive loading cycles without any degradation of the eCE while maintaining high efficiency (coefficient of performance) and adiabatic temperature changes as high as 27 K. This is the largest, directly measured, durable eCE for any elastocaloric material in the high-cycle fatigue regime to date, and so opens up new avenues in the development of durable and efficient elastocaloric devices.

• Jezik: Angleški jezik
• Ključne besede: elastocaloric effect, shape memory alloys, fatigue life, compressive loading, buckling
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FS - Fakulteta za strojništvo ; NTF - Naravoslovnotehniška fakulteta
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2020
• Št. strani: 9 str.
• Številčenje: Vol. 20, art. 100712
• PID: 20.500.12556/RUL-116755
• UDK: 519.6:620.178(045)
• ISSN pri članku: 2352-9415
• DOI: 10.1016/j.apmt.2020.100712
• COBISS.SI-ID: 18414339
• Datum objave v RUL: 08.06.2020

Gradivo je del revije

• Naslov: Applied materials today
• Založnik: Elsevier
• ISSN: 2352-9415
• COBISS.SI-ID: 527289625

Licence

• Licenca: CC BY-NC-ND 4.0, Creative Commons Priznanje avtorstva-Nekomercialno-Brez predelav 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by-nc-nd/4.0/deed.sl
• Opis: Najbolj omejujoča licenca Creative Commons. Uporabniki lahko prenesejo in delijo delo v nekomercialne namene in ga ne smejo uporabiti za nobene druge namene.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: elastokalorični učinek, zlitine z oblikovnim spominom, doba trajanja, tlačno obremenjevanje, uklon

Projekti

• Financer: EC - European Commission
• Program financ.: H2020
• Številka projekta: 803669
• Naslov: Superelastic Porous Structures for Efficient Elastocaloric Cooling
• Akronim: SUPERCOOL