|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Alloys and Compounds for Thermoelectric and Solar Cell Applications X
||Development of Low–defect Single Crystalline Ferromagnetic Shape Memory Alloy for Magnetic Cooling and Actuation
||Wan-Ting Chiu, Pimpet Sratong-On, Masaki Tahara, Volodymyr Chernenko, Hideki Hosoda
|On-Site Speaker (Planned)
The internal degrees of freedom and shape change of the ferromagnetic shape memory alloys (FSMA) are controllable by the magnetic field. Therefore, magnetic cooling and high–speed actuators are considered to be practiced by using the FSMA–based materials. NiMnGa alloys are promising FSMA materials; however, the high brittleness issue of NiMnGa alloys restrains their applicability. In this study, the separators, such as S or Bi, were intentionally inserted into the grain boundaries of the polycrystalline NiMnGa alloys to further embrittle the NiMnGa alloys. The embrittled polycrystalline NiMnGa alloys were then mechanically crushed into single crystal powders at certain elevated temperature. The conventional difficulties, such as high concentration of defects and time–consuming processes for the preparations of single crystals, were solved by using this technology of grain powder preparation. Single crystalline NiMnGa powders were utilized to manufacture different composites for magnetic cooling and high–speed actuator applications.
||Composites, Magnetic Materials, Phase Transformations