Complex mechanism of anelastic relaxation in ternary Fe-20(Al+Ga) alloys

Anelastic relaxation at elevated temperatures (300–600 °C) in binary and ternary Fe-20(Al+Ga) alloys is experimentally studied and analyzed. Two transient effects due to the irreversible annihilation of quenched vacancies and reversible order (short range D03 ↔ disorder A2) transition overlap with thermally activated Zener relaxation due to reorientation of substitution atoms under the stress applied. ‘Map’ of these effects at heating and cooling for sub-resonance Hertz-range frequencies is built to demonstrate similarities between binary Fe-Al, Fe-Ga, and ternary Fe-Al-Ga alloys. Influence of chemical composition and measuring frequency on these effects and their combination is analyzed. Zener relaxation in the ternary alloy is discussed in terms of contribution from Al-Al, Ga-Ga, and Al-Ga atom pairs.