Effects of heat treatment process on microstructure and mechanical properties of Mg-5Zn-xEr alloys

The effects of heat treatment on microstructures and mechanical properties of the Mg-5Zn-xEr alloys (x = 0.63, 1.25, 6.3 wt.%) have been investigated by using XRD, DSC, SEM and TEM. The investigation suggested that the kinds of the secondary phases had a great effect on microstructures and ageing responses of the alloys. It was found that the Mg-5Zn-0.63Er alloys which contained the secondary phase of I-phase exclusively displayed the optimal ageing responses at 175°C for 36 h when it had been solution treated at 480°C for 10 h. However, the Mg-5Zn-1.25Er alloy including both W-phase and I-phase exhibited its good ageing behaviors at 175°C for 10 h after solution treated 520°C for 10 h. Meanwhile, the Mg-5Zn-6.3Er alloy presented its preferable ageing responses at 175°C for 18 h after solution treated at 520°C for 10 h. The peak hardness was ascribed to the presence of the β'1 phase which precipitateed during aging process. © 2012 SPIE.

Duke Scholars

Author Zhaohui Wang Pathology