J Mater Sci Technol ›› 2009, Vol. 25 ›› Issue (05): 649-654.

• Articles • Previous Articles     Next Articles

Effect of Alloying Elements on Microstructure, Martensitic Transformation and Mechanical Properties of Ni-Mn Based Alloys

K. Alvarez, H.Y. Kim, S. Miyazaki   

  1. 1) Graduate School, University of Tsukuba, Ibaraki 305-8573, Japan
    2) Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
  • Received:2008-03-05 Revised:2009-07-01 Online:2009-09-28 Published:2009-10-10
  • Contact: Alvarez Kelly

Abstract:

The microstructural features, shape memory behavior and mechanical properties of Ni-Mn based alloys were investigated by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermal cycling test under various stresses. The transformation temperatures shifted toward lower temperatures when adding a third element into the Ni-Mn system. The addition of 10 at. pct Fe increased considerably the mechanical properties exhibiting still high transformation temperatures. However, it was found that in NiMn40Fe10 alloy the martensitic transformation is not thermoelastic in nature. The mechanism of this transformation and the crystallography of Ni-Mn(50-x)-Fex (x=5, 7, 10, 20 at. pct) alloys are presented.

Key words: Ni-Mn based alloys, Martensitic transformation temperature, L10 phase