Effect Of Heat Treatment And Fe Content On The Damping Capacity Of Mn-Cu Alloy

The Mn5o.35-Cu(48.1-x)-Al1.55-Fex(x=0、1.5、2.5) alloys were prepared by medium frequency vacuum induction melting technique. The heat treatment and Fe content influences on damping capacity of alloys were investigated by optical microscope, X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and the torsion pendulum device. The martensite starting temperature (Ms) and lattice constant and microstructure were analyzed to reveal the mechanism of Mn-Cu damping alloys.After the solid solution at 840℃ for 0.5h, Mn50.35-Cu48.1-Al1.55 alloys were aged at different temperatures and holding times. The results show that the damping capacity of samples increase at first and then decrease with the increasing temperature and holding time. The optimal damping capacity of alloys reaches at 0.055 after aging at 430℃ for 1h(tancp=0.055). More rich-Mn areas result in the higher Ms, consequently the increase of damping capacity.After the solid solution at 840℃ for 0.5h, Mn5o.35-Cu(48.1-x)-Al1.55-Fex (x=0、1.5、2.5) were aged at 460℃ for 1h. The results show that the damping capacity decreases by adding Fe atoms in the alloys. The solid-soluted Fe atoms retard the diffusion of Mn atoms and restrain the spinodal decomposition, resulting in the decrease of Ms and the damping capacity.In the research, the heat treatment of Mn5o.35-Cu45.i-Al1.55-Zn3 can make the alloys’damping capacity higher. And the damping capacity of the samples further increases with the longer holding time. This is due to the more rich-Mn areas forming in spinodal decomposition process. As a result, a higher damping capacity was achieved.