Microstructure, martensitic transformation and elastocaloric effect in Pd-In-Fe polycrystalline shape memory alloys

• Published in: Intermetallics 2018-09, Vol.100, p.27-31
• Main Authors: Shen, Qi, Zhao, Dewei, Sun, Wen, Wei, Zhiyang, liu, Jian
• Format: Article
• Language: English
• Subjects: Alloys; Constitution; Cooling effects; Elastocaloric effect; Iron; Martensitic stainless steel; Martensitic transformation; Martensitic transformations; Materials elasticity; Microstructure; Morphology; Pd-In-Fe; Polycrystals; Rare earth elements; Shape effects; Shape memory alloys; Superelasticity; Transformation temperature
• ISSN: 0966-9795; 1879-0216
• DOI: 10.1016/j.intermet.2018.05.018

In this work, we have investigated the microstructure, martensitic transformation, and elastocaloric effect of Pd-In-Fe polycrystalline alloys. For this new magnetic shape memory alloys, both phase constitution and morphology highly depend on the Fe content. Exhibiting a single austenite phase at room temperature, Pd59.3In23.2Fe17.5 alloy has a large superelastic cooling effect of −5.4 K with a low critical stress of 80 MPa to trigger the martensitic transformation. Interestingly, the onset of superelastic stress can be drastically reduced by mechanical training. The rare-earth/Mn-free and non-toxic element constitution, good ductility and tunable transformation temperature render the Pd-In-Fe Heusler system as a promising candidate for elastocaloric cooling. [Display omitted] •Pd59.3In23.2Fe17.5 alloy is a single austenite phase at room temperature.•Pd59.3In23.2Fe17.5 alloy has a large superelastic cooling effect of -5.4 K with a low critical stress of 80 MPa to trigger the martensitic transformation.•The mechanical training in Pd-In-Fe alloy can drastically reduce the critical superelastic stress, which decreases from 187 to 40 MPa and then tends to stabilize.