Effect of long period stacking ordered (LPSO) structure on the damping capacities of Mg-Cu-Mn-Zn-Y alloys

The microstructure and damping capacities of the Mg-3%Cu-1%Mn-1.8%Zn-x%Y alloys have been researched and compared synthetically. This study showed long period stacking ordered (LPSO) structure is conducive to yield strength and damping capacities on the whole. The Mg-3%Cu-1%Mn-1.8%Zn-12.5%Y can be classified as high damping metals (Q (1) >= 0.01) when strain is above 1.1 x 10(4). When a number of long period stacking ordered structure are observed, the phenomenon both its damping capacities and yield strength increase breaks the contradiction between damping capacities and mechanical properties in magnesium alloys. The damping capacities of those alloys cannot only be explained by the Granato-Lucke theory and a new damping mechanism that depends on frequency has been found. Thereby, it may introduce a new method to produce magnesium alloys with high damping capacity and high strength. (C) 2012 Elsevier B.V. All rights reserved.