Open Access
Experimental observation of vacancy-assisted martensitic transformation shift in Ni-Fe-Ga alloys
(American Physical Society, 2019) Unzueta, Iraultza; Alonso de Robador Lorente, Daniel; Cesari, Eduard; Sánchez-Alarcos Gómez, Vicente; Recarte Callado, Vicente; Pérez de Landazábal Berganzo, José Ignacio; García, José Ángel; Plazaola, Fernando; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias
Positron annihilation lifetime spectroscopy is used to experimentally demonstrate the direct relationship between vacancies and the shift of the martensitic transformation temperature in a Ni55Fel7Ga28 alloy. The evolution of vacancies assisting the ordering enables shifts of the martensitic transformation up to 50 K. Our results confirm the role that both vacancy concentration and different vacancy dynamics play in samples quenched from the L2(1) and B2 phases, which dictate the martensitic transformation temperature and its subsequent evolution. Finally, by electron-positron density functional calculations V-Ni is identified as the most probable vacancy present in Ni55Fe17Ga28. This work evidences the capability of vacancies for the fine-tuning of the martensitic transformation temperature, paving the way for defect engineering of multifunctional properties.
Open Access
Effect of high-energy ball-milling on the magnetostructural properties of a Ni45Co5Mn35Sn15 alloy
(Elsevier, 2021) López García, José Luis; Sánchez-Alarcos Gómez, Vicente; Recarte Callado, Vicente; Rodríguez Velamazán, José Alberto; Unzueta, Iraultza; García, José Ángel; Plazaola, Fernando; La Roca, Paulo Matías; Pérez de Landazábal Berganzo, José Ignacio; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias; Gobierno de Navarra / Nafarroako Gobernua, PC017-018 AMELEC
The effect of high-energy ball-milling on the magnetostructural properties of a Ni45Co5Mn35Sn15 alloy in austenitic phase at room temperature has been analyzed by neutron and high-resolution X-ray diffraction. The ball milling promotes a mechanically-induced martensitic transformation as well as the appearance of amorphous-like non-transforming regions, following a double stage; for short milling times (below 30 min), a strong size reduction and martensite induction occur. On the opposite, for longer times, the increase of strains predominates and consequently a larger amount of non-transforming regions appears. The effect of the microstructural defects brought by milling (as dislocations) on both the enthalpy change at the martensitic transformation and the high field magnetization of the austenite has been quantitatively estimated and correlated to the internal strains. Contrary to what occurs in ternary Ni-Mn-Sn alloys, the mechanically-induced defects do not change the ferromagnetic coupling between Mn atoms, but just cause a net reduction on the magnetic moments.
Open Access
Entropy change caused by martensitic transformations of ferromagnetic shape memory alloys
(MDPI, 2017) L'vov, Victor A.; Cesari, Eduard; Kosogor, Anna; Torrens Serra, Joan; Recarte Callado, Vicente; Pérez de Landazábal Berganzo, José Ignacio; Física; Fisika
In this paper, our most recent findings on the influence of magnetic order on the main transformational caloric and elastic properties of shape memory alloys (SMAs) are reviewed. It is argued that ferromagnetic order has a strong influence on the temperature interval of martensitic transformation (MT), the characteristics of stress-induced MT, and the shear elastic modulus of SMA. The problem of separation of the magnetic contributions to the entropy change ΔS and heat Q exchanged in the course of martensitic transformation (MT) of SMA is considered in general terms, and theoretical formulas enabling the solution of the problem are presented. As an example, the ΔS and Q values, which were experimentally determined for Ni-Mn-Ga and Ni-Fe-Ga alloys with different Curie temperatures TC and MT temperatures TM, are theoretically analyzed. It is shown that for Ni-Mn-Ga martensites with TM < TC, the ratio of elastic and magnetic contributions to the entropy change may be greater or smaller than unity, depending on the temperature difference TC – TM.
Open Access
Magnetically activated 3D printable polylactic acid/polycaprolactone/magnetite composites for magnetic induction heating generation
(Springer, 2023) Galarreta Rodríguez, Itziar; López Ortega, Alberto; Garayo Urabayen, Eneko; Beato López, Juan Jesús; La Roca, Paulo Matías; Sánchez-Alarcos Gómez, Vicente; Recarte Callado, Vicente; Gómez Polo, Cristina; Pérez de Landazábal Berganzo, José Ignacio; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Additive manufacturing technology has attracted the attention of industrial and technological sectors due to the versatility of the design and the easy manufacture of structural and functional elements based on composite materials. The embedding of magnetic nanoparticles in the polymeric matrix enables the development of an easy manufacturing process of low-cost magnetically active novel polymeric composites. In this work, we report a series of magnetic composites prepared by solution casting method combining 5 to 60 wt.% of 140 ± 50 nm commercial Fe3O4 nanoparticles, with a semi-crystalline, biocompatible, and biodegradable polymeric blend made of polylactic acid (PLA) and polycaprolactone (PCL). The composites were extruded, obtaining 1.5 ± 0.2 mm diameter continuous and flexible filaments for fused deposition modelling 3D printing. The chemical, magnetic, and calorimetric properties of the obtained filaments were investigated by differential scanning calorimetry, thermogravimetric analysis, magnetometry, and scanning electron microscopy. Furthermore, taking advantage of the magnetic character of the filaments, their capability to generate heat under the application of low-frequency alternating magnetic fields (magnetic induction heating) was analyzed. The obtained results expose the versatility of these easy manufacturing and low-cost filaments, where selecting a desired composition, the heating capacity can be properly adjusted for those applications where magnetic induction plays a key role (i.e., magnetic hyperthermia, drug release, heterogeneous catalysis, water electrolysis, gas capture, or materials synthesis).
Open Access
Analysis of the strain misfit between matrix and inclusions in a magnetically tunable composite
(Elsevier, 2021) Bonifacich, Federico Guillermo; Lambri, Osvaldo Agustín; Lambri, Fernando Daniel; Bozzano, P. B.; Recarte Callado, Vicente; Sánchez-Alarcos Gómez, Vicente; Pérez de Landazábal Berganzo, José Ignacio; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias; Gobierno de Navarra / Nafarroako Gobernua; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
A magnetically tunable composite has been elaborated by embedding microparticles of a metamagnetic shape memory alloy on a photo curable resin. The strain misfit between the polymeric matrix and the inclusions has been analysed within Eshelby formalism. Results show the non-appearance of active microcracks at the interfaces where strains are induced by the martensitic transformation in the microparticles. Even though the martensitic transformation is well detected, the values of misfit β coefficient indicate that the matrix accommodates all the stresses induced by the inclusions. A stable surface interaction between particles and matrix is also confirmed during thermal cycles. It is also demonstrated that the damping capacity of the composites can be tuned by combining oscillating strain, fillers content and magnetic field. The proposed model could be applied to analyse the mechanical stability in polymer matrix composites in which fillers undergo a first order transition with volume change and associated deformation.
Open Access
High functional 3D printed PCL/FSMA magnetic composites
(IOP Publishing, 2024) Lambri, Fernando Daniel; Bonifacich, Federico Guillermo; Lambri, Osvaldo Agustín; Khanna, Deepali; Pérez de Landazábal Berganzo, José Ignacio; Recarte Callado, Vicente; Sánchez-Alarcos Gómez, Vicente; Lambri, Melania Lucila; Zelada, Griselda Irene; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2
The capacity of adaptability of a three-dimensional-printed composite of polycaprolactone-based containing micro-particles of ferromagnetic shape memory alloy of composition Ni45Mn36.7In13.3Co5 was determined. Composites exhibit an increase in both damping and modulus values up to around 11%, at temperatures close to 325 K, when applying a magnetic field of 120 kA m−1. In addition, composites show also an increase in the damping values of around 50% at temperatures near 333 K, related to the martensitic transformation, which is promoted by an increase in the oscillating strain from 0.5 × 10−4 up to 2 × 10−4 and when applying a magnetic field of 120 kA m−1. Moreover, the maximum temperature of use of the composite can be increased by means of a magnetic field. These adaptability qualities make this functional composite attractive, for the vibration control at elevated temperatures as well as the potential applications in magnetocaloric devices.
Open Access
Polycaprolactone/MSMA composites for magnetic refrigeration applications
(Wiley, 2024-09-06) Sánchez-Alarcos Gómez, Vicente; Khanna, Deepali; La Roca, Paulo Matías; Recarte Callado, Vicente; Lambri, Fernando Daniel; Bonifacich, Federico Guillermo; Lambri, Osvaldo Agustín; Royo Silvestre, Isaac; Urbina Yeregui, Antonio; Pérez de Landazábal Berganzo, José Ignacio; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2
A high filling load (62% weight) printable magnetic composite has been elaborated from the dispersion of magnetocaloric Ni45Mn36.7In13.3Co5 metamagnetic shape memory alloy microparticles into a PCL polymer matrix. The composite material has been prepared by solution method, resulting in a very homogeneous particles dispersion into the matrix. The structural transitions in the polymer are not affected by the addition of the metallic microparticles, which in turn results in a significant increase of the mechanical consistency. The good ductility of the elaborated composite allows its extrusion in flexible printable filaments, from which 3D pieces with complex geometries have been grown. The heat transfer of the composite material has been assessed from finite element simulation. In spite of the achievable magnetocaloric values are moderated with respect to the bulk, numerical simulations confirm that, in terms of heat transference, a PCL/Ni-Mn-In-Co wire is more efficient than a bulk Ni-Mn-In-Co cubic piece containing the same amount of magnetic active material. The quite good magnetocaloric response of the composite and the possibility to print high surface/volume ratio geometries make this material a promising candidate for the development of heat exchangers for clean and efficient magnetic refrigeration applications.
Open Access
Study of the martensitic transition in Ni-Mn-Sn-Ti ferromagnetic shape memory alloys
(Rede Latino-Americana de Materiais, 2018) Bonifacich, Federico Guillermo; Lambri, Osvaldo Agustín; Pérez de Landazábal Berganzo, José Ignacio; Recarte Callado, Vicente; Sánchez-Alarcos Gómez, Vicente; Fisika; Institute for Advanced Materials and Mathematics - INAMAT2; Física; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In the present work, mechanical spectroscopy measurements as a function of temperature and strain have been performed in (at.%) Ni50Mn37Sn13-xTix (x=0, 0.5 and 2) ferromagnetic shape memory alloys in order both to study martensitic transition phenomenon and also to determine its temperature of appearance. For mechanical spectroscopy measurements, a five elements piezoelectric device recently developed has been used. In addition, other characterization techniques as, differential thermal analysis and superconducting quantum interference magnetic spectroscopy, were also used. Besides, relaxation processes near the martensitic transition temperature have been also observed.
Open Access
Martensitic transformation controlled by electromagnetic field: from experimental evidence to wireless actuator applications
(Elsevier, 2022) Garayo Urabayen, Eneko; La Roca, Paulo Matías; Gómez Polo, Cristina; Sánchez-Alarcos Gómez, Vicente; Recarte Callado, Vicente; Pérez de Landazábal Berganzo, José Ignacio; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias; Gobierno de Navarra / Nafarroako Gobernua
Mechanical actuators based on shape memory alloys (SMA) are becoming a key component in the development of novel soft robotic applications and surgically implantable devices. Their working principle relies in the temperature induced martensitic transformation (MT), which is responsible of the actuation mechanism. In this work, we found experimental evidence to show that the martensitic transformation can be controlled by electromagnetic field (EF) by a wireless process in ferromagnetic shape memory alloys. It is shown that the martensitic transformation can be driven by an external EF (frequency 45 kHz) while the specific absorption rate (SAR), which was determined through real-time dynamic magnetization measurements, allows the instantaneous monitoring of the transformation evolution. On the basis of the obtained results, we propose a strategy to achieve a battery-free wireless SMA actuator that can be remotely controlled. This concept can be applicable to other SMA material that exhibit a similar magneto-structural phase transition
Open Access
Monitoring structural transformations in metamagnetic shape memory alloys by non-contact GMI technology
(IOP Publishing, 2023) Beato López, Juan Jesús; La Roca, Paulo Matías; Algueta-Miguel, Jose M.; Garayo Urabayen, Eneko; Sánchez-Alarcos Gómez, Vicente; Recarte Callado, Vicente; Gómez Polo, Cristina; Pérez de Landazábal Berganzo, José Ignacio; Ciencias; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute for Advanced Materials and Mathematics - INAMAT2; Institute of Smart Cities - ISC; Zientziak; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Different applications based on metamagnetic shape memory alloy (MSMA) require monitoring the evolution of the martensitic transformation (MT) to optimize the actuation mechanism. To avoid interaction with the active material, a non-contact technique would be ideal. Nevertheless, non-contact detection involves complex methods like diffraction, optical analysis, or electromagnetic technology. The present work demonstrates that the MT can be monitored without interaction with the active material using a low-cost technology based on the Giant Magnetoimpedance (GMI) effect. The GMI sensor is based on a (CoFe)SiB soft magnetic wire submitted to an alternating current and whose second harmonic voltage variation allows to detect changes in the strength of the stray magnetic fields linked to the metamagnetic phase transition. The sensor has been tested using the MT of a NiMnInCo MSMA. A specific application for environmental temperature control using the non-contact GMI sensor is proposed.