Effect of stacking fault probability and ε martensite on damping capacity of Fe–16%Mn alloy

The damping capacity of a Fe–16%Mn–1%Mg–2%Si (wt.%) alloy has been studied with respect to factors like stacking fault probability, ε martensite, and cold rolling. It was found that the damping capacity of 8% cold rolled specimen is much higher than 0% cold rolled specimen. In the 0% rolled specimen, the stacking faults are responsible for the damping capacity characterized by the large amplitude dependence. The improvement in damping capacity by cold rolling is attributed to the formation of ε martensite. As the temperature increases, the damping capacity improves, reaching its maximum around 1000 °C. A further increase in the temperature, however, degrades the damping capacity. The area of the γ/ε boundaries is the major factor for damping capacity. Heat treatment at 1100 °C reduces the number of ε martensite plates, leading to area reduction of γ/ε boundaries despite an increase in amount of ε martensite.