(1. 上海交通大学 轻合金精密成型国家工程研究中心，上海 200240；
2. 上海交通大学 金属基复合材料国家重点实验室，上海 200240)
摘 要: Mg-Gd系合金的时效析出强化效果优异且析出序列及析出相在含稀土镁合金中具有一定代表性。总结了国内外Mg-Gd系合金时效析出的研究进展，阐述该系合金的时效析出动力学、析出序列及析出相、析出相强化机理等。影响Mg-Gd系合金时效析出动力学的主要因素有时效温度、Gd元素含量、晶粒尺寸、预变形量以及少量非稀土合金元素的添加等。Mg-Gd、Mg-Gd-Y(Dy)、Mg-Gd-Nd(Sm)等合金系的时效析出序列依次为β″-Mg3Gd→β′-Mg7Gd→β1-Mg3Gd→β-Mg5Gd，Mg-Gd-Zn合金时效过程中则还会有γ″-Mg70Gd15Zn15相和γ′-MgGdZn相存在。最后，对该系合金的析出强化机制和未来的发展方向进行了阐述。
关键字: Mg-Gd系合金；时效析出动力学；析出相；力学性能；强化机制
（1. National Engineering Research Center of Light Alloy Net Forming,
Shanghai Jiao Tong University, Shanghai 200240, China;
2. Key State Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:Mg-Gd alloys have an excellent ageing precipitation strengthening effect, their precipitation sequence and precipitate phases are also very typical in magnesium alloys containing rare earth elements. The research progress on ageing precipitation of Mg-Gd alloys was reviewed in three aspects: ageing precipitation kinetics are ageing temperature, Gd contents, grain size, different deformation, little addition amount of RE element. The precipitation sequence of Mg-Gd, Mg-Gd-Y(Dy), Mg-Gd-Nd(Sm) series alloys during ageing is basically β″-Mg3Gd→β′-Mg7Gd→ β1-Mg3Gd→β-Mg5Gd, there are also precipitates γ″-Mg70Gd15Zn15 and γ′-MgGdZn in Mg-Gd-Zn alloy. At last, the precipitation strengthening mechanism and further development of Mg-Gd alloys were discussed.
Key words: Mg-Gd alloys; ageing precipitation kinetics; precipitate; mechanical property; strengthening mechanism
