Effect of Zr content on damping property of Mg-Zr binary alloys

The damping property expressed by internal friction tan phi of as-cast Mg-Zr binary alloys with Zr content from 0.6 to 5.0% was experimentally measured under conditions of changing temperature from ambient temperature T-am to 600 K (327 degrees C), vibration frequency f from 1.0 to 10.0 Hz, strain epsilon from 1.0 x 10(-6) to 1.0 x 10(-3), and heating rate v from 2 to 5 K/min. The experimental results indicate that the damping property of prepared as cast Mg-Zr binary alloys can be effectively promoted by increasing either heating rate v or strain epsilon. Increasing vibration frequency f can effectively decrease the damping property, however increasing vibration frequency f has little effect on the plots of internal friction tan phi against temperature T, i.e., T-tan phi curve, under the condition of f > 5.0 Hz. The optimal Zr content of the as-cast Mg-Zr binary alloys with better performance of damping property is recommended to be 0.6 mass % in a range of Zr content from 0.6 to 5.0%. Furthermore, the effect of strain epsilon on damping property for the as-cast Mg-Zr binary alloys can be ideally explained by dislocation pinning theory or the G-L model, while the influence of temperature T on damping property for the as-cast Mg-Zr binary alloys complies with the viscoelastic relaxation behaviour.