Anelasticity in Fe-Ga based alloys in the range of Zener relaxation

Reference Speaker Authors
SEVERINE A.E. BOYER BOYER, S.A.(MINES ParisTech, PSL - Research University); Gerland, M.(PPRIME Institute, ISAE- ENSMA); Riviere, A.(PPRIME Institute, ISAE- ENSMA); Cifre, J.(Universitat de les Illes Balears); Palacheva, V.V.(National University of Science and Technology); Golovin, I.S.(National University of Science and Technology); Zener relaxation is studied in binary and ternary Fe-Ga based alloys. Several regularities are proved: i. Concentration dependence of Zener relaxation in binary Fe-Ga alloys, ii. Transient internal friction contribution in the same range with Zener relaxation, iii. Zener relaxation in ternary Fe-Ga-Al alloys: frequency- vs temperature dependent internal friction. Activation energies and pre-exponential time t0 for the Zener relaxation are measured by using both temperature- (dynamical mechanical analyser DMA Q800 TA Instruments) and frequency- (forced torsion pendulum) dependent internal friction tests (frequency variations from 10-4 to 102 Hz). Especially focussed on iii., the measurements of frequency- vs temperature dependent internal friction are conducted for Fe-13Ga binary and Fe-12Ga-5Al ternary alloys in the metastable (as cast or quenched) and equilibrium states. Transient effects are avoided by using frequency dependent internal friction tests at selected temperatures. The Arrhenius treatment of relaxation effects in single- and polycrystals allows to identify the Zener effects in ternary alloys and to analyse them with respect to alloy structures.
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