An ultrahigh strain-independent damping capacity in Mg–1Mn alloy by cold rolling process

Abstract

An ultrahigh strain-independent damping in Mg–1Mn alloy was prepared by cold rolling process. Combined with microstructure characterization, the mechanical properties and damping capacities of Mg–1Mn alloy with different reduction were systematically investigated. By the appropriate cold rolling process, numerous parallel dislocations, stacking faults (SFs) and a few non-basal <c> dislocations are introduced into Mg matrix. Due to the non-basal <c> dislocations and stacking faults coexists with basal <a> dislocations, their reaction with each other leads to the activation of more non-basal slips and increase of strain hardening rate, which simultaneously improves the strength and plasticity of Mg–1Mn alloy. On the other hand, the increase of number of moveable dislocations and SFs, acting as dissipated source, effectively improves the damping capacity. Especially, the Mg–1Mn alloy shows an ultrahigh strain-independent damping capacity, which outperforms the high-damping Mg-0.6Zr alloy. When the reduction is 20%, the alloys show a good comprehensive mechanical properties: the ultimate tensile strength (UTS), the yield strength (YS) and plasticity is 206 MPa, 156 MPa and 49.8%. This work provides a new strategy for preparing high-strength, high-plasticity and high-damping magnesium alloy.