Enhancement of the microstructure and mechanical properties in as-forged Mg–8Al–0.5Zn alloy using T5 heat treatment

Abstract

This paper mainly concerns about the effect of T5 heat treatment on the microstructure and mechanical properties of the as-extruded as well as as-forged Mg–8Al–0.5Zn alloy which was produced by the warm forging process for the Mg tie-rod at the temperature of 523K. In the as-forged microstructure, rate of hardness increase from the initial to the peak hardness is substantially slow compared with the as-extruded since it already has a large amount of the precipitates in the warm forging process, which reduces the rate of precipitate hardening. Both types of precipitates such as the discontinuous lamellar- and continuous particle-types are favored simultaneously with the increase of aging time even though it is aged at the lower temperature of 450K.