Effect of Mn content on microstructure and damping capacity of Fe-Mn alloy

Fe-Mn alloys were prepared by high frequency induction melting in a vacuum atmosphere.The damping capacity was measured using reversal torsion pendulum.The effect of Mn content on microstructure and damping capacity of Fe-Mn alloy was investigated,combining with SEM and TEM.The results indicated that the damping capacity increased with increasing Mn content,attained a maximum at approximately 16.5%Mn,and then decreased with further Mn content.When Mn content is less than 16.5%,with Mn content increasing,the quantity of extended dislocation increased,and at the same time,the mobility increased with the quantity of α′ martensite decreasing,which both leaded to increasing damping capacity.When Mn content is more than 16.5%,the damping capacity decreased for the quantity of extended dislocation decreasing with increasing Mn content.