Papers by Author: Fan Zhang

Abstract: Supersaturated Mg-Gd-Y alloy followed by aging at 225 °C with different times were subjected to quais-static and dynamic strain rates to determine the influence of precipitate phase β′ on the strain rate sensitivity of magnesium alloy. Strain rate sensitivity (SRS) decreases with the increase of the size of β′. SRS decreases from initial condition to peak-aged condition due to the β′ increases the athermal component of flow stress. On the other hand, the influence of precipitate interfaces on dislocation generation and storage mechanisms may be responsible for the decrease of SRS from peak-aged to over-aged condition.

Abstract: Effects of anisotropy on the microstructural characteristics and mechanical behavior of shock loaded of AZ31 magnesium alloy have been investigated. Using electron backscatter diffraction, tension twinning was observed in both shock loading directions along the normal (ND) and rolling directions (RD). Compression tests were carried out along ND and RD in both as-received and post-shock conditions. It indicated that the RD samples show a more notable hardening behavior compared to the as-received conditions. Moreover, it is postulated here that detwinning results in a drop of strain-hardening rate for the ND samples under post shock reload conditions and tension twinning formed during the shock wave loading process leads to a significant moving left of the peak strain hardening rate for the RD samples under post shock reload conditions.