应力和温度的耦合作用，可改变原子在固溶体/过饱和固溶体中的扩散速度、方向和数量，从而有效的控制析出相的数量、尺寸、分布及与基体的位相关系，获得单一作用下难以出现的新现象、新规律和新性能。本项目拟深入分析应力和温度的耦合作用对Mg-Dy-Zn合金中长周期有序相(LPSO)的析出行为和增强作用的影响。采用X射线、扫描和透射电镜表征LPSO相的组成、结构及与镁基体的位相关系，揭示LPSO相在应力和温度耦合作用下的形成机理，进而采用维氏硬度计及纳米压痕仪测定合金及LPSO相的宏观/微观硬度，研究LPSO相的析出行为，并利用INSTRON 拉伸机测试合金在不同温度和应变速率下的拉伸性能，研究合金的变形行为，深入分析LPSO相的增强作用，最终绘制出应力-温度-性能的三维谱图。

Under the coupling of stress and temperature fields, the atomic diffusion rate, diffusion direction and volume fraction occur to change in solid solution/super solid solution, which leads the corresponding change in the volume fraction, scale, distribution and orientation relationship of the precipitate with Mg matrix. A new phenomena, law and property will be also found in the above two conditions but not do in the single one. In this study, the influnces of coupling of stress and temperature fields on the precipitation behavior and strengthening role of long period stacking ordered (LPSO) phase in the Mg-Dy-Zn alloy were investigated greatly. Composition, structure and orientation relationship of the LPSO phas with Mg matrix were characterized by using X-ray Diffraction, Scanning Electric Microscope and Transmission Electron Microscope to reveal the formation mechanism of the phase under coupling of the stress and temperature fields. Furthermore, Macro/micro hardness of the alloy and LPSO phase was measured by using Vickers hardness tester and Nanoindentation instrument to investigate the precipitation behavior of the LPSO phase. Tensile properties were tested by using INSTRON machine tester to study the deformation behavior of the alloy and clarify greatly the strengthening role of the LPSO phase at different strain rates and temperatures. Finally, the three-dimensional pattern of Stress-Temperature-Mechanical Property would be drawn.