TY  - JOUR
AU  - Zhang, N.B.
AU  - Wang, W.Z.
AU  - Lu, L.
AU  - Li, Ke
AU  - Yang, Kun
AU  - Yang, T.
AU  - Zhao, X.J.
AU  - Zeng, Ying
AU  - Luo, S.N.
PY  - 2026
TI  - High strain rate deformation and spall damage in a Mg-Ag-Nd-Zr alloy: Effects of δ/γ precipitates
JO  - Journal of Magnesium and Alloys
SN  - 2213-9567
VL  - 17
IS  - C
AB  - Plate impact experiments are conducted on aging-treated (AG) and solution-treated (ST) QE22 Mg alloy (Mg-2.5Ag-2.0Nd-0.7Zr) to investigate the effects of precipitates with different sizes on deformation and spall damage properties/mechanisms. The AG alloy contains the micron-scale intermetallic precipitates (δ) at grain boundaries and nano-scale precipitates (γ) in the matrix, while the ST alloy contains only the δ precipitates. Given the γ precipitate strengthening, the dynamic yield stress for the AG alloy (0.173 GPa) is about 40 % higher than that for the ST alloy (0.122 GPa). Upon shock loading,  {1012}, {1011} and {1121} deformation twins are observed, and the γ precipitates significantly impede the growth of twins. The spall damage features of both samples are characterized and summarized via two dimensional scanning electron microscopy and three dimensional X-ray computed tomography. The voids/cracks are basically restricted within the δ phase at grain boundaries. In the AG alloy, the additional back-stress from matrix strengthened via γ precipitates suppresses void growth, leading to the less severe spall damage and 20 % higher spall strength (0.58–0.63 GPa) compared to the ST alloy (0.48–0.51 GPa). The present study provides insights into the roles of δ/γ precipitates in dynamic deformation and spallation of QE22 Mg alloy. Nano-scale γ precipitates improve both dynamic yield stress and spall strength, while micron-scale δ precipitates are conducive to the nucleation of spallation voids.
UR  - https://doi.org/10.1016/j.jma.2025.10.023
DO  - 10.1016/j.jma.2025.10.023