Microstructure evolution and corrosion resistance of high-pressure rheo-cast Mg-Zn-Y alloy containing quasicrystal

The effects of high pressure applied during rheo-squeeze casting (RSC) process on the microstructure evolution and corrosion resistance of Mg90.8Zn8.6Y0.6 alloy were investi-gated. The results reveal that with the increase of pressure, both the average size of a-Mg grains and the lamellar spacing of in-situ formed quasicrystal phase (I-Mg3Zn6Y) are continuously decreased. Meanwhile, the high-pressure results in the increase in the su-persaturation of Zn in matrix, the decrease in volume fraction of second phases and the disappearance of Mg7Zn3 phase. The high-pressure contributed to the improvement of corrosion resistance, and the corrosion process was changed from three stages (galvanic corrosion, filiform corrosion and pitting corrosion) to two stages (galvanic corrosion and pitting corrosion), which was mainly attributed to the supersaturation of Zn in matrix, the continuous distribution of finer I-phase and the disappearance of Mg7Zn3.& COPY; 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).