(1. 北京工業(yè)大學 循環(huán)經濟研究院，北京 100124；
2. 北京工業(yè)大學 材料科學與工程學院，北京 100124)
摘 要: 以Mg-6Al合金為基體，分別單一添加稀土Nd、Sr和復合添加稀土Nd和堿土Sr元素，采用水冷模工藝制備Mg-6Al-6Nd，Mg-6Al-2Sr和Mg-6Al-2Sr-2Nd耐熱鎂合金，并比較研究單一添加Nd或Sr和復合添加稀土Nd和堿土Sr對合金組織結構和蠕變性能的影響。結果表明：復合添加稀土Nd和堿土Sr后，合金中除了析出第二相Al2Nd、Al11Nd3和Al4Sr外，還析出Sr和Nd相互取代的Al4(Sr,Nd)和Al11(Nd,Sr)3復合相；在Mg-6Al-2Sr基礎上添加2%Nd，不僅細化合金枝晶間距，還顯著地提高第二相的分布密度，增強合金蠕變過程中位錯與第二相交互作用，提高合金的蠕變性能。
關鍵字: 鎂合金；耐熱鎂合金；堿土；稀土；耐熱性；蠕變性能
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
