Microstructure evolution, damping capacities and mechanical properties of novel Mg-xAl-0.5Ce (wt%) damping alloys

Abstract

The effect of Al content on the microstructure, damping behavior and mechanical properties of Mg-xAl-0.5Ce (wt%) damping alloys was systematically studied. Al content had a great effect on the morphology features of Al4Ce phases. The quasi-rectangular network structure was observed in as-cast Mg-1Al-0.5Ce alloy. The Al addition promoted the dynamic recrystallization during extrusion process and led to the texture weakening, but the basal texture was sharpened with further Al addition due to the consumption of the Ce solute. The as-extruded Mg-1Al-0.5Ce alloy showed the best damping capacity among as-extruded Mg-xAl-0.5Ce alloys, which was mainly ascribed to the texture weakening. The ductility was improved with increasing Al content, while the strength was reduced. This behavior was related with the texture weakening and increasing grain sizes. The as-extruded Mg-1Al-0.5Ce alloy exhibited the excellent comprehensive performance. The peak P2 of as-extruded alloys in the first heating run was a superimposed peak, consisting of a grain boundary relaxation peak and a recrystallization peak. The grain boundary peaks P2 in the second heating run shifted to lower temperatures and their activation energies decreased with increasing Al content. The reasons for the variation of the grain boundary peak P2 were discussed.