微量Er对Mg-Nd-Zn-Zr合金显微组织与力学性能的影响  

Effects of Trace Er Addition on Microstructure and Mechanical Properties of As-cast Mg-Nd-Zn-Zr Alloy

作　　者：梁叔全[1] 陈亮[1] 官迪凯[1] 陈涛[1] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《热加工工艺》2012年第2期1-4,共4页Hot Working Technology

基　　金：国家自然科学基金资助项目(50774097);国家自然科学基金创新研究群体科学基金资助项目(50721003)

摘　　要：利用光学显微镜、扫描电镜、透射电镜、能谱仪、X射线衍射分析及力学性能测试,研究了稀土元素Er对Mg-Nd-Zn-Zr合金铸态显微组织及力学性能的影响。结果表明:在Mg-Nd-Zn-Zr合金中添加0.5wt%Er后,元素Er主要以白色小颗粒形貌分布在晶间,合金达到峰值时效的时间更短,且有大量细小的相均匀析出,时效强化效果更好;加入Er后,合金抗拉强度、屈服强度和伸长率分别达到283.4、170.2 MPa和4%;在Mg-Nd-Zn-Zr-Er合金室温拉伸断口中有高度不一的解理台、撕裂棱和少量韧窝,韧窝中的颗粒物主要含Er、Nd,说明该合金具有较好的塑性;Er的加入并没有改变合金的断裂方式,两种合金时效态都以准解理断裂为主。The effects of trace Er addition on the microstructure and mechanical properties of as-cast Mg-Nd-Zn-Zr alloy were investigated by optical microscopy,scanning electron microscopy,transmission electron microscope,energy-dispersive spectroscopy,X-ray diffractometry and mechanical properties test.The results show that Mg-Nd-Zn-Zr alloy with addition of Er 0.5wt% has small white particles of Er disperse in the grain boundaries.The alloy with Er reaches the peak-aged hardness sooner than that without Er,and lots of uniform fine phase precipitates,so its aging strengthening response is better with Er.As Er is added into Mg-Nd-Zn-Zr alloy,the tensile strength,yield strength and elongation is 283.4 MPa,170.2 MPa and 4%,respectively.There are some rugged cleavage plates,tear ridges and a few dimples in the room temperature fracture surface images of Mg-Nd-Zn-Zr-Er alloy.The particles in the dimples mainly include Er and Nd,which show that the alloy with Er has a good plasticity.Er addition does not change the fracture behavior of Mg-Nd-Zn-Zr alloy and the fracture modes of the both alloys after aging-treatment are quasi-cleavage in major.

关 键 词：稀土Er Mg-Nd-Zn-Zr合金 显微组织 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]