含长周期有序结构相(LPSO)的Mg-RE-Zn合金力学性能优异，有望取代部分铝和钢铁结构材料，进而推动工业构件的轻量化进程。然而，LPSO相作为合金强韧化的关键因素，亦具有窄化可成形工艺区间的副作用，使合金生产与推广受到阻碍。本项目以提升Mg-RE-Zn合金热成形能力为驱动，突破转变LPSO相结构这一方案成效微弱、可行性欠佳的瓶颈，提出通过调控LPSO相形貌以诱导合金动态再结晶进而提升其热成形能力的新思路。首先，利用热处理和预变形等手段调控LPSO相形貌，基于显微组织观察及热、动力学分析，探明LPSO相形貌的演变规律及机制，确保形貌调控的可重复性与稳定性；其次，辨析各种LPSO相形貌与合金动态再结晶行为的对应关系，揭示LPSO相形貌对合金热成形的单独和协同作用机制；最后，构建“LPSO相形貌—动态再结晶行为—热成形能力”关联模型，为含LPSO相镁合金的热成形工艺规程优化设计奠定理论基础。

Mg-RE-Zn alloys with long-period stacking ordered (LPSO) phases exhibit excellent mechanical properties, which increases the possibility to partly replace aluminum and steel structural materials by magnesium alloys and accelerates the lightweight process for industrial components. However, as a key factor for strengthening and toughening, LPSO phase simultaneously has the side effect of significantly narrowing the formable parameter ranges of Mg-RE-Zn alloys, which hinders their production and application. For sake of enhancing the hot workability of Mg-RE-Zn alloys, this project proposes a new solution of promoting dynamic recrystallization (DRX) and then improving hot workability by regulating the morphologies of LPSO phases, which breaks through the bottleneck of weak effectiveness and poor feasibility that exists in the traditional method of adjusting the LPSO structure. Firstly, the morphologies of LPSO phases will be controlled by means of heat treatment and predeformation, etc. The basic law and mechanism for the morphology evolution will be explored by microstructure observation combined with thermal and kinetic analysis, in order to ensure the repeatability and stability of the morphology regulation. Secondly, the relationship between varies morphologies and DRX behavior will be carefully discriminated to figure out the single and combined effects of LPSO morphologies on the hot workability. Finally, a correlation model of “LPSO morphology-DRX behavior-hot workability” will be constructed to lay the theoretical foundation for optimizing the processing parameters of the magnesium alloys which contain LPSO phases.