Microstructure and mechanical properties of the Mg–Gd–Zn alloy prepared by sintering of rapidly-solidified ribbons

Abstract

Mg–15Gd–1Zn (wt.%) alloy was successfully prepared via the spark plasma sintering rapid solidification ribbons process. Microstructure investigation showed that the sintered alloys consisted of fine grains, the β1 phase, and long-perioded stacking ordered phase (LPSO). The sintering temperature and time have a significant effect on the microstructural evolution. A lower sintering temperature (430 °C ) was beneficial for obtaining finer grain sizes with less than 5 μm and a higher content of β1 phase with a content of 3–15 vol.% and a size-distribution of (10–600) nm. A higher temperature for a longer sintering time, 450–470 °C and 5–10 min, helpfully promoted precipitating the abundantly lamellar LPSO phase, and its content was 2–10 vol.% for LPSO phase with the width of (10–100) nm. The mechanical properties indicated that the fine grain size and supersaturated solid solution contributed at least 50% of the yield stress, and the residual contribution was related to the β1 phase and LPSO phase strengthening, which were based on their contents and the sizes.