Effect of Aging Treatment on Dynamic Behavior of Mg-Gd-Y Alloy

Abstract

Magnesium alloy is very attractive in many industrial applications due to its low density. The structure-property relationships of the magnesium alloy under quasi-static loading have been extensively investigated. However, the dynamic behavior, particularly the mechanism of high-rate plastic deformation, of the magnesium alloy requires more in-depth investigations. In this paper, the effect of aging treatment on the quasi-static and dynamic properties of a typical rare earth Mg-Gd-Y magnesium alloy is investigated. In particular, the plastic deformation mechanism under dynamic compression loading is discussed. Split Hopkinson Pressure Bar (SHPB) was used to carry out dynamic compression tests with controllable plastic deformation by using stopper rings. The experimental results demonstrate that both static and dynamic properties of the Mg-Gd-Y alloy vary under various aging treatment conditions (under-aged, peak-aged and over-aged conditions), due to two different kinds of second phases: remnant micro size phase from solid solution treatment and nano precipitation from aging treatment. The results of microstructure characterization and statistic analysis of the metallographic phase are presented. The area fraction of the twinned grains increases due to aging treatment and dynamic loading. The main plastic deformation mechanism of the rare earth Mg-Gd-Y magnesium alloy is possibly dislocation slip, rather than twinning for the conventional AZ31 magnesium alloy under high strain rate loading.

Fatigue of rare‐earth containing magnesium alloys: a review

“…e and f) show that mainly round‐shaped particles containing more Zr appeared in the T6 state. Similar observations were also reported by Wang et al . Based on the Mg–Gd phase diagram and Mg–Y phase diagram, only one single phase solid solution would be expected in the Mg‐10Gd‐3Y‐0.5Zr (GW103K) alloy during solution treatment at 500 °C.…”

“…3e and f) show that mainly round-shaped particles containing more Zr appeared in the T6 state. Similar observations were also reported by Wang et al 76 Based on the Mg-Gd phase diagram 51 and Mg-Y phase diagram, 79 only one single phase solid solution would be expected in the Mg-10Gd-3Y-0.5Zr (GW103K) alloy during solution treatment at 500°C. It was reported that the solubility of Gd and Y in Mg at 500°C was about 20wt% and 10wt%, respectively, 51 whereas the solubility of Zr in Mg was very limited.…”

“…c) seemed to be higher as compared to the regular RE‐rich particles in the T5 alloy due to the ageing process. Wang et al . also reported that the square‐shaped second particles were mostly rich with Gd and Y, and round‐shaped second particles were rich with Zr, which actually concurred the results of the GW103K alloy in both as‐extruded and T5 states.…”