中文摘要：

利用光学显微镜、X射线衍射仪、扫描电镜,研究了稀土Nd对AZ80镁合金组织和力学性能的影响。AZ80镁合金铸态组织由基体α-Mg和晶界处析出的粗大连续网状β-Mg17Al12相组成。添加Nd后,使原本粗大连续的β-Mg17Al12相转变为细小和断续分布,同时,合金中产生了形态分别呈杆状的Al11Nd3相和块状的Al2Nd稀土相。随着Nd元素添加量的增加,AZ80镁合金的铸态力学性能呈先提高后下降的趋势。当加入0.9%的Nd时,合金的铸态抗拉强度和屈服强度均达到最高,分别为205MPa和135MPa,伸长率达到7.5%。时效过程中稀土元素Nd抑制了片状β-Mg17Al12相的不连续析出,延迟合金达到峰时效的时间。T6处理后,AZ80-0.6Nd合金的抗拉强度和屈服强度最高,分别为221MPa和164MPa,伸长率为4.1%。

英文摘要：

Effects of RE element Nd on microstructure and mechanical properties of AZ80 magnesium alloy were analyzed by OM（optical microscopy）,XRD（X-ray diffraction）and SEM（scanning electron microscopy）.The as-cast microstructure of AZ80 alloy consists ofα-Mg matrix andβ-Mg17Al12 phase which appears in form of coarse network at grain boundaries.With addition of Nd,coarse continuousβ-Mg17Al12 phase is refined and becomes discontinuous,and a new rod-shaped Al11Nd3 phase and blockshaped Al2 Nd phase occur in alloy.Under as-cast conditions,with the increase of Nd addition,the mechanical properties of AZ80 magnesium alloy is increased firstly and then decreased.With the Nd content of 0.9%,the tensile strength,yield strength and elongation of the magnesium alloy are increased to 205 MPa,135 MPa and 7.5%,respectively.During aging treatment,the addition of Nd can suppress the discontinuous precipitation of plate-likeβ-Mg17Al12 phase at grain boundaries,and the time of reaching the peak hardness is delayed.After T6 heat treatment,the tensile strength,yield strength and elongation of AZ80-0.6Nd alloy are increased to 221 MPa,164 MPa and 4.1%,respectively.