(1. 北京工业大学 循环经济研究院，北京 100124；
2. 北京工业大学 材料科学与工程学院，北京 100124)
摘 要: 以Mg-6Al合金为基体，分别单一添加稀土Nd、Sr和复合添加稀土Nd和碱土Sr元素，采用水冷模工艺制备Mg-6Al-6Nd，Mg-6Al-2Sr和Mg-6Al-2Sr-2Nd耐热镁合金，并比较研究单一添加Nd或Sr和复合添加稀土Nd和碱土Sr对合金组织结构和蠕变性能的影响。结果表明：复合添加稀土Nd和碱土Sr后，合金中除了析出第二相Al2Nd、Al11Nd3和Al4Sr外，还析出Sr和Nd相互取代的Al4(Sr,Nd)和Al11(Nd,Sr)3复合相；在Mg-6Al-2Sr基础上添加2%Nd，不仅细化合金枝晶间距，还显著地提高第二相的分布密度，增强合金蠕变过程中位错与第二相交互作用，提高合金的蠕变性能。
关键字: 镁合金；耐热镁合金；碱土；稀土；耐热性；蠕变性能
heat-resistant Mg-Al-Nd/Sr alloys
（1. Institute of Recycling Economy, Beijing University of Technology, Beijing 100124 , China;
2. College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China）
Abstract:By single addition of Nd or Sr, and combined addition of Nd and Sr into Mg-6Al matrix alloys, heat-resistant Mg-6Al-6Nd, Mg-6Al-2Sr and Mg-6Al-2Sr-2Nd were obtained by water cooled technology, respectively. The microstructures and creep properties of water-cooled Mg-6Al-2Sr-2Nd alloys were analyzed and compared to reveal the effects of addition means. The results show that when the Nd and Sr elements are added into the Mg-6Al matrix alloy together, there occur the complicated compound named Al4(Sr,Nd) with part Sr substituted by Nd and the complicated compound named Al11(Nd,Sr)3 with part Nd substituted by Sr precipitate besides the compound Al11Nd3 and Al2Nd formed in the Mg-6Al-6Nd alloy and Al4Sr formed in the Mg-6Al-2Sr alloy. In the Mg-6Al-2Sr alloy, the addition of 2%Nd not only refines its grains and dendrite spacing but also improves the distribution density of all precipitates, which leads to the stronger interaction between the dislocation and precipitates in the creep process and improves its creep properties.
Key words: magnesium alloy; heat-resistant magnesium; alkaline earth; rare earth; heat-resistance; creep property
