(Mg,Zn)3Gd precipitates were observed in the form of parallel arrays within a α-Mg matrix of a Mg-3.5Gd-1Zn-0.6Zr (GZ41K) alloy following isothermal holding at 450 °C for 20 min or uniaxial hot compression testing at 450 °C and at strain rates of 10− 3 s− 1 and 10− 1 s− 1. A microstructural analysis using a combination of scanning and transmission electron microscopies showed arrays of precipitates nucleated on stacking faults as a result of the LPSO structures decomposing statically after long isothermal holding times at 450 °C, which is lower than the dissolution temperature of (Mg,Zn)3Gd precipitates (520 °C), and dynamically, as a result of hot compression. The presence of precipitates on slip bands was also observed in the case of deformed specimens. The characteristics of the precipitates were investigated using differential thermal analysis, and optical and electron microscopy. The influences of the solutionizing temperature and deformation conditions on distribution, morphology and volume fraction of precipitates were quantified. The results are interpreted in terms of the influence of the strain rate in increasing the stacking fault/dislocation intersections and the decomposition of the L12 structure of stacking faults.

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