Microstructure Dependence and Molecular Dynamics Simulation of Damping Mechanism for Fe–Mn Alloy

The microstructure dependence of damping performance for Fe−17 pct Mn alloy was investigated by combining rapid solidification experiments and molecular dynamics (MD) simulation. It was found that high cooling rate increased stacking fault probability and Shockley partial dislocations. The refined microstructures incorporated much more crystal defects such as interphase or grain boundaries and stacking faults, in addition to dislocations. The damping property was consequently improved with the further effect of forming martensitic phases. MD simulations revealed that both the probability density function of “fast atoms” and the damping capacity were enhanced by rapid solidification. It was also demonstrated that “fast atoms,” which are always inherited in fertile defects areas, were the intrinsic mechanism for damping property. The influences of microstructural evolution and atomic motion on damping performance coincided with each other.