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.