(1. 河南科技大学 材料科学与工程学院，洛阳 471003；
2. 河南省有色金属材料科学与加工技术重点实验室，洛阳 471003；
3. 上海理工大学 机械工程学院，上海 200093)
摘 要: 研究在AZ31B变形镁合金中添加稀土Nd对AZ31B合金铸态和热轧退火态性能及组织的影响。结果表明：在AZ31B变形镁合金中添加Nd后，合金的铸态和热轧退火态的室温抗拉强度和伸长率均降低；加入的Nd与Al形成Al2Nd相，Nd还可以与Al和Mn形成Al-Nd-Mn化合物，剩余的Al还可以和Mg形成Mg17Al12相。含Al和Mn的金属间化合物削弱元素Al、Mn对镁合金的晶粒细化作用导致晶粒粗大，进而降低铸态AZ31B合金性能；热稳定性好的粗大第二相的出现也是导致合金铸态性能降低的原因，增大变形量使第二相得到充分破碎，会使板材力学性能得到改善。
关键字: 变形镁合金；AZ31镁合金；稀土；第二相
of AZ31B wrought magnesium alloy
（1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China;
2. Henan Key Laboratory of Advanced Non-ferrous Metals, Luoyang 471003, China;
3. College of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China）
Abstract:The effects of rare earth Nd on the microstructures and mechanical properties of as-cast and hot-rolled AZ31B wrought magnesium alloy were investigated. The results show that the mechanical properties of both as-cast and hot-rolled AZ31B alloys at room temperature decrease due to rare earth Nd addition. When rare earth Nd is added into AZ31B alloy, the Nd reacts with Al element to form Al2Nd phase, the Nd may also reacts with Mn and Al to form Al-Nd-Mn intermetallics compounds, the residual Al reacts with Mg to form Mg17Al12 phase. The intermetallics compound containing Al and Mn weakens the grain refinement effect of Al and Mn on AZ31B alloy and results in the declining of mechanical properties of as-cast AZ31B alloy. The thermostable and bulky second phase is another main reason for the declining the mechanical properties of as-cast AZ31B alloy. The bulky second phase is the main reason to result in the declining of mechanical properties of hot-rolled sheet of AZ31B alloy. The mechanical properties of hot-rolled sheet of AZ31B-0.8Nd alloy can be improved through increasing the strain of hot rolling because the second phase are adequately refined by large deformation.
Key words: wrought magnesium alloy; AZ31 Mg alloy; rare earth; second phase
