Effect of Mn Concentration on Magneto-mechnaical Properties in Directionally Solidified Ferromagnetic Shape Memory Ni-Mn-Ga Alloys

  • R.K Singh Defence Metallurgical Research Laboratory, Hyderabad
  • M. Manivel Raja Defence Metallurgical Research Laboratory, Hyderabad
  • P. Ghosal Defence Metallurgical Research Laboratory, Hyderabad
  • R.P. Mathur Defence Metallurgical Research Laboratory, Hyderabad
Keywords: Ferromagnetic shape memory alloys, directional solidification, martensitic transformation, magnetic field induced strains

Abstract

Heusler type alloys Ni50Mn25+xGa25-x  (x=2,3,4 and 5) based on near stoichiometric Ni2MnGa compositions were directionally solidified using modified Bridgman method. The alloys thus prepared were characterized for their chemical composition, crystal structure, microstructure, phase transformation, magnetic  and magneto-mechanical properties. The directionally solidified Ni50Mn30Ga20 alloy rod exhibited maximum magnetocrystalline value of 95 kJm-3 and lowest detwinning stresses for martensite phase of about 5MPa. The reversible room temperature magnetic field induced strain of 0.2% under external magnetic field of 0.6T and 0.05kN bias load was obtained for the directionally solidified Ni50Mn30Ga20 alloy.
Published
2016-06-28
How to Cite
SinghR., RajaM., GhosalP., & MathurR. (2016). Effect of Mn Concentration on Magneto-mechnaical Properties in Directionally Solidified Ferromagnetic Shape Memory Ni-Mn-Ga Alloys. Defence Science Journal, 66(4), 391-402. https://doi.org/10.14429/dsj.66.10214