Elastic response of ferromagnetic shape memory alloys in the vicinity of the critical point

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F19%3A00334846" target="_blank" >RIV/68407700:21340/19:00334846 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Elastic response of ferromagnetic shape memory alloys in the vicinity of the critical point

Popis výsledku v původním jazyce

The Ni-Fe-Ga-Co ferromagnetic shape memory alloy system has recently gained attention for exhibiting anhysteretic stress-strain behaviour, related to a critical point of the martensitic transformation (MT). This Thesis reports an experimental investigation of the Ni50.1Fe25.4Ga20.0Co4.5 (at.%) and Ni48.3Fe26.2Ga20.2Co5.2 (at.%) in terms of the thermomechanical properties with a special focus on the vicinity of the critical point. Differential scanning calorimetry, vibrating sample magnetometer and dynamical mechanical analysis were used to examine magnetic anomalies, elastic modulus and thermal effects near MT and to determine the martensitic transformation temperatures. The quasi-static stress-strain and strain-temperature dependencies were studied to disclose the critical behaviour from the point of view of MT stress hysteresis and transformation strain evolutions, respectively. The dependence of elasticity on temperature and compressive stress was examined by resonant ultrasound spectroscopy and surface acoustic wave velocity measurements.

Název v anglickém jazyce

Elastic response of ferromagnetic shape memory alloys in the vicinity of the critical point

Popis výsledku anglicky

The Ni-Fe-Ga-Co ferromagnetic shape memory alloy system has recently gained attention for exhibiting anhysteretic stress-strain behaviour, related to a critical point of the martensitic transformation (MT). This Thesis reports an experimental investigation of the Ni50.1Fe25.4Ga20.0Co4.5 (at.%) and Ni48.3Fe26.2Ga20.2Co5.2 (at.%) in terms of the thermomechanical properties with a special focus on the vicinity of the critical point. Differential scanning calorimetry, vibrating sample magnetometer and dynamical mechanical analysis were used to examine magnetic anomalies, elastic modulus and thermal effects near MT and to determine the martensitic transformation temperatures. The quasi-static stress-strain and strain-temperature dependencies were studied to disclose the critical behaviour from the point of view of MT stress hysteresis and transformation strain evolutions, respectively. The dependence of elasticity on temperature and compressive stress was examined by resonant ultrasound spectroscopy and surface acoustic wave velocity measurements.

Druh

O - Ostatní výsledky

CEP obor

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OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

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Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů