R&D: Magnetic-Field-Induced Transformation and Strain in Polycrystalline FeMnGa Ferromagnetic Shape Memory Alloys With High Cold-Workability

Applied Physics Letters has published an article written by Yajiu Zhang, School of Civil Engineering, Guangzhou University, Guangzhou 510006, China, and Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China, Zhigang Wu, School of Civil Engineering, Guangzhou University, Guangzhou 510006, China, Zhipeng Hou, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China, Zhuhong Liu, Department of Physics, University of Science and Technology Beijing, Beijing 100083, China, Enke Liu, Xuekui Xi, Wenhong Wang, and Guangheng Wu, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.

Abstract: “Poor mechanical properties severely impede the practical application of ferromagnetic shape memory alloys. In this Letter, we report cold deformation-induced B2-γ phase transformation in polycrystalline FeMnGa alloys. Due to this property, the alloy achieved a high strength of ∼1000 MPa and a ductility of ∼75% in a compressive test, and a 90% deformation in thickness in a cold rolling experiment, indicating excellent cold-workability. The recrystallization annealing transformed the cold rolled γ phase to a textured B2 phase, which exhibited magnetic-field-induced phase transformation and anisotropic transformation strains. These properties indicate that FeMnGa is a promising candidate for future applications in actuator devices.“

This work was supported by the National Natural Science Foundation of China (No. 51771225), the Natural Science Foundation of Guangdong Province (No. 2018A030313742), the Science and Technology Plan Project of Guangzhou (No. 202102020934), and the Science and Technology Planning Project of Gansu Province of China (No. 17JR5RA223).