Damping capacity in Fe-Mn binary alloys

The damping capacities of Fe-Mn binary alloys have been investigated in a wide range of manganese content from 5 to 30 wt%. The damping capacity increases with increasing manganese content, attains a maximum at approximately 17 wt%Mn, and decreases with further manganese content. It is suggested that the damping mechanisms of Fe-Mn alloys containing γ and ε phases are the stress-induced movement of the defects: stacking fault boundary in γ, stacking fault boundary in ε, ε martensite variant boundary, γ/ε interphase boundary. The appearance of the maximum damping capacity at around 17 wt%Mn in Fe-Mn binary system is well explained with the damping mechanisms. The contributions of the damping mechanisms to the overall damping capacities of Fe-17 wt%Mn and Fe-21 wt%Mn alloys are quantitatively analyzed, which indicates that ε martensite bears the major part of their damping capacities.