(1. 四川工程職業(yè)技術(shù)學院 材料工程系，德陽 618000； 2. 重慶大學 國家鎂合金材料工程技術(shù)研究中心，重慶 400044； 3. 重慶理工大學 材料科學與工程學院，重慶 400054； 4. 中國核動力研究設(shè)計院 核燃料及材料國家重點實驗室，成都 610041)
摘 要: 鍶元素加入到鎂合金中能夠起到變質(zhì)第二相，顯著細化晶粒以及提高其高溫力學性能的效果，已被廣泛應(yīng)用于Mg-Al系鎂合金中。綜述了國內(nèi)外在含鍶Mg-Al系合金中的第二相研究現(xiàn)狀，實驗研究結(jié)果和第一性原理計算結(jié)果均表明，隨著Sr含量的增加，Mg-Al系合金中將首先出現(xiàn)Al-Sr相(Al4Sr相和/或Al2Sr相)，然后再出現(xiàn)Mg-Sr相((Mg,Al)17Sr2相)和/或Mg-Al-Sr三元相。但是，其中Mg-Al-Sr三元相的結(jié)構(gòu)和類型尚存在爭議。綜述相圖熱力學計算以及第一性原理計算方法在含鍶Mg-Al系合金中第二相研究方面的結(jié)果，將第一性原理計算與相圖熱力學模擬有機結(jié)合起來，可以獲得更為準確的含鍶鎂合金二元或三元系相圖。
關(guān)鍵字: 鎂合金；鍶；第二相；第一性原理；相圖計算
（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
