Effect of long period stacking ordered structure on the damping capacities of Mg-Ni-Y alloys

The microstructure and damping capacities of the Mg-Ni-Y alloys were researched and compared synthetically. This study showed that long period stacking ordered (LPSO) structures were conducive to the overall damping capacities. Mg-8.51%Ni-15.25%Y can be classified as high damping metals (Q−1≥0.1) at strains exceeding 1×10−3. With increased LPSO phase, the critical strain amplitudes of alloys gradually decreased so that the alloys could more easily break away from pinning. In addition, the strain amplitude-independent damping and strain amplitude-dependent damping of the Mg-Ni-Y alloys both increased. The damping capacities of the alloys cannot be explained by the Granato-Lücke theory alone.