Martensitic Transformation and Crystal Structure Characterization of Ni-Fe-Ga-Co Ferromagnetic Shape Memory Alloys

Abstract:

In this paper, the martensitic transformation temperature, the microstructure and the crystal structure of the complicated martensitic phases of Ni_56-xFe₁₉Ga₂₅Co_x (x =0, 1.5, 3, 4.5, 6) alloys were investigated by DSC, XRD, SEM and TEM techniques. DSC results show that the martensitic transformation temperature T_m, which is above the room temperature, decreases with the increasing Co content. The microstructure of the Ni_56-xFe₁₉Ga₂₅Co_x (x =0, 1.5, 3, 4.5, 6) alloys is composed by the martensitic lath and randomly distributed γ phase. The 6M+14M mixed modulated martensite and the γ second phase were detected in the Ni₅₃Fe₁₉Ga₂₅Co₃ alloy by XRD and TEM tests.

• Periodical: Materials Science Forum (Volume 879)
• Pages: 2061-2065
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.879.2061
• Online since: November 2016
• Authors: Pan Jiang, Jing Bai*, Pu Wei, Shuang Ji Han, Mei Jie Yang, Fei Teng, Xin Li Wang, Xiang Zhao
• Keywords: Crystal Structure, Ferromagnetic Shape Memory Alloy, Martensitic Transformation, Microstructure, Ni-Fe-Ga-Co

References

[1] H. Morito, A. Fujita, K. Fukamichi, et al, Magnetic-field-induced strain of Fe-Ni-Ga in single-variant state, Appl. Phys. Lett. 83 (2003) 4993-4995.

DOI: 10.1063/1.1632039

[2] H. Morito, A. Fujita, K. Oikawa, et al, Stress-assisted magnetic field induced strain in Ni-Fe-Ga-Co ferromagnetic shape memory alloys, Appl. Phys. Lett. 90 (2007) 062505.

DOI: 10.1063/1.2450667

[3] H. Morito, K. Oikawa, A. Fujita, et al, Effects of partial substitution of Co on magnetocrystalline anisotropy and magnetic-field-induced strain in NiFeGa alloys, J. Magn. Magn. Mater. 290-291 (2005) 850-853.

DOI: 10.1016/j.jmmm.2004.11.392

[4] K. Oikawa, T. Ota, T. Ohmori, et al, Magnetic and martensitic phase transitions in ferromagnetic Ni-Ga-Fe shape memory alloys, Appl. Phys. Lett. 81 (2002) 5201-5203.

DOI: 10.1063/1.1532105

[5] H. X. Zheng, M. X. Xia, J. Liu, Martensitic transformation of (Ni55. 3Fe17. 6Ga27. 1)100-xCox magnetic shape memory alloys, Acta Mater. 53 (2005) 5125-5129.

DOI: 10.1016/j.actamat.2005.07.023

[6] H. X. Zheng, J. Liu, M. X. Xia, et al, Martensitic transformation of Ni-Fe-Ga-(Co, Ag) magnetic shape memory alloys, J. Alloy. Compd. 387 (2005) 265-268.

DOI: 10.1016/j.jallcom.2004.06.088

[7] H. Morito, K. Oikawa, A. Fujita, et al, Enhancement of magnetic-field-induced strain in Ni-Fe-Ga-Co Heusler alloy, Scripta Mater. 53 (2005) 1237-1240.

DOI: 10.1016/j.scriptamat.2005.08.009

[8] J. Liu, N. Scheerbaum, D. Hinz, et al, Martensitic transformation and magnetic properties in Ni-Fe-Ga-Co magnetic shape memory alloys. Acta Mater. 56 (2008) 3177-3186.

DOI: 10.1016/j.actamat.2008.03.008

[9] J. H. Sui, Z. Y. Gao, et al, Martensitic and magnetic transformations of Ni56Fe17Ga27-xCox high-temperature ferromagnetic shape memory alloys, Scripta Mater. 59 (2008) 874-877.

DOI: 10.1016/j.scriptamat.2008.06.036

[10] P. J. Brown, J. Crangle, T. Kanomata, et al, The crystal structure and phase transitions of the magnetic shape memory compound Ni2MnGa, J. Phys.: Condens. Mat. 14 (2002) 10159-10171.

DOI: 10.1088/0953-8984/14/43/313

[11] F. Masdeu, J. Pons, C. Segui, et al, Some features of Ni-Fe-Ga shape memory alloys under compression, J. Magn. Magn. Mater. 290-291 (2005) 816-819.

DOI: 10.1016/j.jmmm.2004.11.371

[12] Z. Y. Zhu, Study on Phase Transition and Magnetization of Ferromagnetic Shape Memory Alloys Ni51. 5Mn25Ga23. 5 and Ni2FeGa, Changchun, China：Jilin University, (2005).

[13] J. Liu, N. Scheerbaum, D. Hinz, et al, A high-temperature coupling of martensitic and magnetic transformations and magnetic entropy change in Ni-Fe-Ga-Co alloys, Scripta Mater. 59 (2008) 1063-1066.

DOI: 10.1016/j.scriptamat.2008.07.019