Formation mechanism of quasicrystals at the nanoscale during hot compression of Mg alloys

A comprehensive transmission electron microscopy investigation was conducted to gain insights into how the secondary phases in Mg–1.50Zn–0.25Gd alloys are transformed during hot compression. It was found that needle-like Mg4Zn7 phases precipitate in Mg matrix, yet vanish during compression, forming nano-quasicrystals. These nano-quasicrystals are found to nucleate on the Mg4Zn7 phase with orientation relationships [112‾0]Mg‖[1‾07]Mg4Zn7|| [2-fold]I-phase, indicating that the crystal phase can transform to the quasicrystalline phase. The formation mechanism of the quasicrystals in Mg alloys at the nanoscale is also discussed.