Martensitic Transformation and Shape Memory Effect of Ni_53.25Mn_21.75Ga₂₅ Ferromagnetic Shape Memory Alloy

Abstract:

The martensitic transformation, crystalline structure, microstructure and shape memory effect of the Ni53.25Mn21.75Ga25 (at.%) alloy are investigated by means of Differential Scanning Calorimetry (DSC), X-ray diffraction (XRD), Transmission Electron Microscope (TEM) and the standard metal strain gauge technique. The XRD results showed that the Ni53.25Mn21.75Ga25 alloy is composed of cubic parent phase at room temperature. TEM observation proved that the typical twin martensite is tetragonal structure and tweed-like contrast which is typical image for the parent phase. A large reversible transformation strain, about 0.54%, is obtained in this undeformed polycrystalline alloy due to martensitic transformation and its reverse transformation. This transformation strain is also increased to 0.65% by the external magnetic field. It is believed that the effect of the magnetic field on the preferential orientation of martensitic variants increases the transformation strain.

• Periodical: Advanced Materials Research (Volumes 476-478)
• Pages: 1504-1507
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.476-478.1504
• Online since: February 2012
• Authors: Hai Bo Wang, Shang Shen Feng, Pei Yang Cai, Yan Qiu Huo
• Keywords: Martensitic Transformation (MT), Microstructure, NiMnGa Alloy, Transformation Strain

References

[1] V.A. Chernenko, E. Cesari, V.V. Kokorin and I.N. Vitenko: Scr. Metall. Mater. Vol. 33 (1995), p.1239

[2] K. Ullakko, J.K. Huang, V.V. Kokorin and R.C. O'Handley: Scr. Mater. Vol. 36 (1997), p.1133

[3] R.C. O'Handley: J. Appl. Phys Vol. 83 (6) (1998), p.3263

[4] J. Worgull, E. Petti and J. Trivisonmo: Phys. Rev. B. Vol. 54 (1996), p.15695

[5] A.N. Vasil'ev, A.D. Bozhko, V.V. Khovailo, I.E. Dikshtein, V.G. Shavrov, V.D. Buchelnikov, M. Matsumoto, S. Suzuki, T. Takagi and J. Tani: Phys. Rev. B. Vol. 59 (1999), p.1113

[6] Y. Feng, J.H. Sui, L. Chen and W. Cai: Materials Letters Vol. 63 (2009), p.965

[7] K. Vallal Peruman, M. Mahendran and S. Seenithurai: Physica B Vol. 405 (2010) p.1770

DOI: 10.1016/j.physb.2010.01.037

[8] G.F. Dong, X.H. Li and W. Cai: Rare Metal Materials and Engineering Vol.39 (2010), p.1785

[9] J. Pons, V.A. Chernenko, R. Santamarta and E. Cesari: Acta Mater Vol. 48 (2000), p.3027

[10] R. Tickle and R.D. James: J. Magn. Magn. Mater. Vol. 195 (1999), p.627

[11] C.M. Wayman: Suppl Trans JIM Vol. 17 (1976), p.159

[12] V.V. Kokorin, V.A. Chernenko, E. Cesari, J. Pons and C. Segui: J. Phys,: Condens. Matter. Vol. 8 (1996),p.6457

DOI: 10.1088/0953-8984/8/35/014