Available online

  (Laboratory for Materials and Structures / Dr. Hideki Hosoda  and Dr. Volodymyr Chernenko)

“Large magnetostrains of Ni-Mn-Ga/silicone composite containing system of oriented 5M and 7M martensitic particles”

Scripta Materialia  (DOI: 10.1016/j.scriptamat.2021.114265)

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<Abstract>
In view of the exponential rate of advancement in robotics technology, a composite material, which is promising for high-speed and large-strain actuation and sensing applications, has been developed in this study. Single-crystalline Ni_49.9Mn_28.5Ga_21.6 (SC Ni-Mn-Ga) ferromagnetic  shape memory alloy  particles were fabricated from the  polycrystalline  Ni-Mn-Ga alloy by a well-controlled mechanical crushing. X-ray diffractions revealed a mixture of 5M- and 7M-martensitic phases in the SC Ni-Mn-Ga particles. A composite consisting of the  silicone  rubber and 20 vol.% of the crystallographically and spatially oriented SC Ni-Mn-Ga particles was fabricated by curing under a magnetic field and the chain-oriented structure was confirmed by a micro-computed  tomography.  This composite, which exhibited a magnetic field induced rubber-like behavior with a magnetostrain as high as 4.0% despite reduced filling factor, was attributed to the co-existence of the 5M- and 7M-martensitic phases.