(1. 四川工程职业技术学院 材料工程系，德阳 618000； 2. 重庆大学 国家镁合金材料工程技术研究中心，重庆 400044； 3. 重庆理工大学 材料科学与工程学院，重庆 400054； 4. 中国核动力研究设计院 核燃料及材料国家重点实验室，成都 610041)
摘 要: 锶元素加入到镁合金中能够起到变质第二相，显著细化晶粒以及提高其高温力学性能的效果，已被广泛应用于Mg-Al系镁合金中。综述了国内外在含锶Mg-Al系合金中的第二相研究现状，实验研究结果和第一性原理计算结果均表明，随着Sr含量的增加，Mg-Al系合金中将首先出现Al-Sr相(Al4Sr相和/或Al2Sr相)，然后再出现Mg-Sr相((Mg,Al)17Sr2相)和/或Mg-Al-Sr三元相。但是，其中Mg-Al-Sr三元相的结构和类型尚存在争议。综述相图热力学计算以及第一性原理计算方法在含锶Mg-Al系合金中第二相研究方面的结果，将第一性原理计算与相图热力学模拟有机结合起来，可以获得更为准确的含锶镁合金二元或三元系相图。
关键字: 镁合金；锶；第二相；第一性原理；相图计算
（1. Department of Materials Engineering, Sichuan Engineering Technical College, Deyang 618000, China; 2. National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044, China; 3. College of Materials Science and Engineering, Chongqing University of Technology, Chongqing 400054, China; 4. National Key Laboratory for Nuclear Fuel and Material, Nuclear Power Institute of China, Chengduo 610041, China）
Abstract:In recent years, Sr alloying/micro-alloying was widely used in Mg-Al-based magnesium alloys due to the benefits on modification of secondary phases, grain size refinement and improvement of elevated temperature properties. The recent research works on secondary phases in strontium-contained Mg-Al series magnesium alloys were summarized. With the Sr contents increasing, Al-Sr phases, such as Al4Sr and Al2Sr, form at first, and then Mg-Sr phases, such as (Mg,Al)17Sr2 and Mg-Al-Sr ternary phases form, which are confirmed by both of the experimental and modelling results. However, the structure and stoichiometry of the Mg-Al-Sr ternary phase are still controversial. At the same time, the results on mechanical properties and stability of the Sr-containing secondary phases, which were calculated by using CALPHAD thermodynamic modeling and first-principles calculations methods, respectively, also were reviewed. In addition, it is considered that combining these two simulation methods, more accurate binary or ternary phase diagrams of Mg-Al-Sr series could be obtained.
Key words: magnesium alloys; strontium; secondary phases; first-principles; calphad calculation
