| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1600775 | Intermetallics | 2011 | 5 Pages |
The high surface/volume ratio and mechanical stability under cyclic strain makes polycrystalline Ni–Mn–Ga metallic foams attractive for magnetic refrigeration. By means of comparison with a polycrystalline bulk material, we have demonstrated that the porous structure of Ni54.8Mn20.2Ga25.0 open-cells metallic foams (porosity varying between 44% and 58%) reduces the temperature span of the phase transition and increases the magnetocaloric effect (MCE). MCE was investigated using calorimetry in a magnetic field. Temperature scan and isothermal experiments have shown a 0.8 K T−1 shift of the phase transition temperature and a maximum irreversible entropy change of 2.5 Jkg−1 K−1. The results indicate that metallic foams can represent a good approach for enhancing field induced phase transitions in magnetic refrigeration applications.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Beneficial effects of a porous structure on phase transitions of shape memory alloys. ► The foam structure doubles the magnetocaloric effect with respect a bulk material. ► This study opens new possibilities on using metallic foams in magnetic refrigeration. ► Calorimetry in magnetic field allows to study magnetocaloric effect in MSMA.
