Influence of Rare Earth on Shape Memory and Martensitic Transformation Behaviors of a FeMnSiCr Alloy
Proper amount of blend rare earth (RE), e.g. less than 0.2 wt%, was added into a Fe25Mn6Si5Cr alloy and showed beneficial effect on its shape memory property. On the other hand, measurements of internal friction revealed that RE-addition reduces the Ms temperature and the amount of thermal-induced martensite. Higher La-content in thin hcp (e) plates than that in fcc (g) matrix was observed by analytical TEM. Thermodynamic calculations also indicated a relatively high equilibrated concentration in e and a strong interaction between La atom and 1/6<112> Shockley dislocation. Except for the grain refinement and solid-solution strengthening effect, the influence of RE on the g ® e martensitic transformation is discussed in taking into account both the Suzuki Effect and Suzuki Lock. The former results in a reduced stacking fault energy, while the Suzuki Lock hinders the movement of Shockley partials and thus the extension of stacking faults.
Z.Y. Zhong, H. Saka, T.H. Kim, E.A. Holm, Y.F. Han and X.S. Xie
X. Huang et al., "Influence of Rare Earth on Shape Memory and Martensitic Transformation Behaviors of a FeMnSiCr Alloy", Materials Science Forum, Vols. 475-479, pp. 1995-1998, 2005