INTERNAL-FRICTION IN FE-MN-CR-SI-NI SHAPE-MEMORY ALLOYS

In this work we have carried out internal friction and modulus measure ments on Fe-Mn-Cr-Si-Ni samples using an inverted torsion pendulum at 1 Hz. The internal friction peaks associated with the martensitic tran sformation are clearly observed in the obtained spectra. Analysis of t he internal friction spectra allowed us to obtain a linear relation be tween the peak area and the heating or cooling rate during the direct and reverse transformations. The evolution of the transformation tempe ratures and the hysteresis of the cycle as well as the area of the int ernal friction peak have been studied vs. the cycling. A general expla nation is discussed that allows us to interpret the whole set of exper imental results.