Effect of Sc addition on the microstructure, mechanical properties, and damping capacity of Al–20Zn alloy

Abstract

In this study, hot rolling (HR), solid solution treatment (ST), and friction stir processing (FSP) were applied to Al–20Zn and Al–20Zn–0.5Sc alloys to obtain their elongated, coarsened, and fine-equiaxed grain structures. Sc addition refined the grains of Al–20Zn alloys in any state. The dynamic precipitation during deformation, such as HR and FSP, was promoted by the Al3Sc phase in the alloy containing Sc. The strength of Al–20Zn alloy was improved by Sc addition. Furthermore, a reasonable ductility was obtained in the ST sample when added with Sc. The fine grains and high density of Al3Sc particles with grain boundary pinning effect resulted in increased high-temperature internal friction value and excellent damping stability of the HR and FSP Al–20Zn–0.5Sc samples.