Microstructure and high-damping property of sintered Mn-Cu alloy

Mn-Cu alloys exhibit high-damping ability after suitable heat treatment. In order to reduce the density and increase the damping and sound absorption abilities, porous Mn-Cu alloys were prepared by powder metallurgy techniques. The contents of alpha-Mn phase decrease with the increasing solution temperature after hydrogen sintering at 1233 K for 1.5 h. The diffraction peaks of the fcc-Mn-Cu are split after solid solution treatment at 1173 K for 1.5h and aging treatment at 723 K for 4 h, which implies the occurrence of spinodal decomposition. The porous Mn-Cu alloys possess a density of 5.8 g/cm(3) (nominal porosity: 22%), a bending strength of 300 MPa, and a high level of damping ability (tan delta from 0.08 to 0.11). The high damping capacity may be due to the combination of the material itself and the porous structure. The Mn-Cu alloy with porous structure and high damping ability could find wide application in the field of vibration and noise reduction.