J. Mater. Sci. Technol. ›› 2020, Vol. 45: 44-48.DOI: 10.1016/j.jmst.2019.10.042

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Intrinsic two-way shape memory effect in a Ni-Mn-Sn metamagnetic shape memory microwire

Zhen Chena, Daoyong Conga,*(), Yin Zhanga, Xiaoming Suna, Runguang Lia, Shaohui Lia, Zhi Yanga, Chao Songa, Yuxian Caoa, Yang Renb, Yandong Wanga,**()   

  1. a Beijing Advanced Innovation Center for Materials Genome Engineering, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China
    b X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
  • Published:2020-05-15 Online:2020-05-27
  • Contact: Daoyong Cong,Yandong Wang


An intrinsic two-way shape memory effect with a fully recoverable strain of 1.0 % was achieved in an as-prepared Ni50Mn37.5Sn12.5 metamagnetic shape memory microwire fabricated by Taylor-Ulitovsky method. This two-way shape memory effect is mainly owing to the internal stress caused by the retained martensite in austenite matrix, as revealed by transmission electron microscopy observations and high-energy X-ray diffraction experiments. After superelastic training for 30 loading/unloading cycles at room temperature, the amount of retained martensite increased and the recoverable strain of two-way shape memory effect increased significantly to 2.2 %. Furthermore, a giant recoverable strain of 11.2 % was attained under a bias stress of 300 MPa in the trained microwire. These properties confer this microwire great potential for micro-actuation applications.

Key words: Metamagnetic shape memory alloys, Two-way shape memory effect, Microwire, Recoverable strain, Microstructure