BUSCADOR RECOLECTA

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., Universidad Nacional de Rosario, Grant/Award Numbers: PPCT-UNR80020220600018UR, PID-UNR80020220700026UR; Ministerio de Ciencia e Innovacion, Grant/Award Numbers:PID2022-138108OB-C32, MCIN/AEI/10.13039/501100011033/FEDER; Consejo Nacional de Investigaciones Científicas y Técnicas, Grant/Award Number: CONICET-PIP11220210100073CO.

4D printing enables the manufacturing of complex smart components in a wide variety of shapes. In devices based on 4D printed composite materials, the interaction between the active microparticles and the printable polymer matrix plays a critical role for the optimal functionality. Key parameters in these materials are the elastic misfit coefficient, which monitors internal stresses, and elastic energy transfer, which determines the ability to transfer strain from the microparticles to the surrounding matrix. In this work, the temperature-dependent shear modulus of PCL/Ni45Mn36.7In13.3Co5 4D printed composites is analysed using the modified rule of mixture (ROM) and Halpin-Tsai (HT) models. The molecular flow caused by the polymer chain movement under oscillatory mechanical stress at relatively elevated temperatures is examined and discussed using these models. Additionally, the effect of an external direct magnetic field on the shear modulus is also analysed. Finally, the internal stresses in the composite materials resulting from the martensitic transformation in the active microparticles are studied through a modified mean-field model based on the Eshelby's inclusion theory., This work was partially supported by PIP-CONICET 11220210100073CO (2022-2024), the PPCT-UNR 80020220600018UR (2023-2026), the PID-UNR80020220700026UR
(2023-2026), the Cooperation Agreement between the Universidad Nacional de Rosario and the Universidad Pública de Navarra, Res. C S 3812/2021 (2021-2026) and the Spanish Agencia Estatal de Investigacion (AEI), Ministerio de Ciencia e Innovacion (Project PID2022-138108OB-C32 (MCIU/AEI/FEDER, UE)).