Effects of Zn content on damping behaviours of Al–Mg alloys

Abstract

Effects of Zn content (0–1.5, in wt.%) on damping capacities of the as-homogenised and the hot-rolled Al–9.2Mg alloys are investigated. The Zn addition plays a significant role in the strain-amplitude-dependent damping (Q_h⁻¹). As for the as-homogenised state, Q_h⁻¹ decreases at first and then increases with the higher Zn content, and the Al–9.2Mg–1.5Zn alloy exhibits the highest Q_h⁻¹ (>0.016). As for the hot-rolled state, Q_h⁻¹ is just the reverse and the Al–9.2Mg–0.5Zn alloy exhibits the highest Q_h⁻¹ (>0.018). The damping behaviours are in accord with the G–L dislocation theory, which are determined by stacking fault energy (SFE), textures and precipitates.