Change in stacking-fault energy with Mn content and its influence on the damping capacity of the austenitic phase in Fe-high Mn alloys

The effect of Mn content on the damping capacity of γ austenitic phase for Fe-(17–28)%Mn alloys has been studied in relation to the stacking-fault energy ( SFE), on the basis of the results of microstructural observations, thermodynamic calculations and vibration tests in a torsional mode. The damping capacity of γ austenite decreases with the increase in the Mn content. The decrease in density of stacking-faults in γ austenite and mobility of the stacking-fault boundary, on which the damping capacity of γ phase depends, is considered to be responsible for the deterioration of damping capacity.