Currently, Mg-Gd-Y-Zn-Zr alloys face the issue of a long aging duration. To establish a short-time aging treatment route, the precipitation characteristics and their effects on mechanical properties during elevated-temperature heat treatment prior to low-temperature aging treatment, low-temperature single-stage aging treatment, and low-temperature two-stage aging treatment were studied. The following results were obtained: Wider intragranular lamellar phases, including 14-LPSO and γ′′ phases, are more easily obtained during long-term holding at heat treatment temperatures of 400 °C and 450 °C. Although these lamellar phases do not contribute to strengthening, they enhance ductility by hindering crack propagation. Micro-sized β phases precipitate more readily at heat treatment temperatures of 300 °C and 350 °C. Intragranular needle-like β phases are not effective strengthening phases, and β phase precipitating along grain boundaries form a networked distribution, which reduces ductility. The nano-sized β' phase, as the main strengthening phase, is more likely to precipitate during single-stage aging at temperatures of 200 °C and 250 °C. The β' phase formed at 200 °C is denser, leading to higher strength, but requiring a longer aging time. For two-stage aging, which involves a primary-stage at 200 °C for 8 to 12 h followed by a second-stage at 250 °C for 10 h, the aging time is reduced to at least one-quarter of that required for single-stage aging at 200 °C, ensuring strength while improving ductility. The formation of very dense nano-sized β' phases during the primary-stage aging facilitates the densification of β' phases during the subsequent second-stage aging. Additionally, the shortened aging time hinders the precipitation of β phase along the grain boundaries, thus improving ductility.

The lightweight of high-end equipment relies on high mechanical properties magnesium (Mg) alloy structural components, because it is the best way to improve equipment service performance and reduce energy consumption. This article summarizes the current progress and characteristics of large-scale high-performance Mg alloy components by analyzing the strengthening-toughening mechanisms, characteristics of plastic forming, and the preparation of large high mechanical properties forging blanks. Due to the lack of breakthroughs in the key technologies for forming large-scale Mg alloy components, their uniformity of mechanical properties and consistency are poor, the forming accuracy of components is low, and the production cost is high, which limit their engineering application and restrict the lightweight level of high-end equipment. In view of the above problems, the forming trends and research directions of large-scale and high mechanical properties Mg alloy components are proposed in this paper. It can provide help for the breakthrough of the key technology of large-scale Mg alloy components with high mechanical properties and expand the application of Mg alloy in high-end products.