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Ferromagnetic Alloys

Shape memory ferromagnetic alloys present very interesting properties, focused on the so-called martensitic transformation. This way, they show many potential applicabilities, in fields such as mechanical engineering or robotics, among others

Within the "Ferromagnetic Alloys" topic, here in the GRPFM we perform exhaustive studies of the martensitic transformation, in collaboration with the research group of the Faculty of Physics in the University of the Balear Islands, led by Dr. Eduard Cesari.

Our first studies in this field were performed in copper based alloys, Cu-Zn-Al, presenting the martensitic transformation between -100ºC and 100ºC and Cu-Al-Ni, with transformation temperatures reaching 200ºC. Cu-Al-Ni alloys are more stable thermically, but also highly fragile and the precipitation of non-martensitic phases limit their applicability.
Alloys belonging to the Ni-Ti family (NI-Ti-Cu, Ni-Ti-Nb) are the most popular as far as they present very good memory shape properties, together with an excelent mechanic and corrosion resistence and a high degree of biocompatibility.

During these last years, we have started to study shape memory alloys in which it is possible to induce the martensitic transformation under the application of a magnetic field (the austentitic phase is a magnetic phase, whether the martensitic one is not). these materials are able to induce big deformations by the application of magnetic fields. We currently are studying the Ni-Mn-Ga and Ni-Fe-Ga alloys.

Our work is focused on the study of the thermal behaviour of the alloy, subjected to different thermal treatments. We do characterize the martensitic transformation by means of calorimetric techniques (usually DSC, but also AC or thermal cycling), analyzing its evolution under different ageing treatments and thermal cyclings.

Here it is listed the collection of articles on Ferromagnetic Alloys