Zn含量对Mg-6Gd-4Y变形镁合金显微组织与力学性能的影响（英文）  

Effect of Zn Content on the Microstructure and Mechanical Properties of the Extruded Mg-6Gd-4Y(wt%) Alloy

作　　者：甄睿[1,2] 孙扬善 沈学为[1] Zhen Rui1,2, Sun Yangshan3, Shen Xuewei1(1.Nanjing Institute of Technology, Nanjing 211167, China; 2 Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing 211167, China; 3 Jiangsu Key Laboratory of Advanced Metallic Materials, Southeast University, Nanjing 211189, China)

机构地区：[1]南京工程学院,江苏南京211167 [2]江苏省先进结构材料与应用技术重点实验室,江苏南京211167 [3]东南大学江苏省先进金属材料高技术研究重点实验室,江苏南京211189

出　　处：《稀有金属材料与工程》2018年第10期2957-2963,共7页Rare Metal Materials and Engineering

基　　金：Research Foundation of Nanjing Institute of Technology(ZKJ201604);Innovative Foundation Project for Students of Nanjing Institute of Technology(TB201702004);Outstanding Scientific and Technological Innovation Team in Colleges and Universities of Jiangsu Province

摘　　要：研究了Mg-6Gd-4Y(质量分数,%)合金与添加质量分数1%Zn的Mg-6Gd-4Y-1Zn合金的显微组织与力学性能。结果表明:Mg-6Gd-4Y合金的铸态组织由?-Mg基体和Mg_(24)(GdY)_5两相组成。而含有Zn的Mg-6Gd-4Y-1Zn合金的铸态组织则主要由α-Mg,Mg_(24)(GdY)_5和具有18R-LPSO结构的Mg_(12)Y_1Zn_1相组成。挤压后,在含锌合金中发现了14H-LPSO相,分布于条状分布的Mg_(12)Y_1Zn_1之间。14H-LPSO相的形成机理为沉淀析出,反应可表示为α-Mg′→α-Mg+14H。Zn含量对β系列沉淀物没有明显的影响。在Mg-6Gd-4Y合金和Mg-6Gd-4Y-1Zn合金上进行的时效(T6和T5)处理均引起β'析出相的形成。T6处理后的Mg-6Gd-4Y-1Zn合金具有高抗拉伸强度和良好的延展性,屈服强度(YS),抗拉强度(UTS)和延伸率分别为309 MPa,438 MPa和6.8%。这是18R-LPSO相与细小弥散分布的14H-LPSO相和β'沉淀相共同作用的结果。Microstructures and mechanical properties of the Mg-6Gd-4Y（wt%）alloys with and without 1wt%Zn additions were investigated.The results show that the as-cast microstructure of the Mg-6Gd-4Y alloy consist of β-Mg matrix and Mg_（24）（GdY）5secondary phase.However,the as-cast microstructure of the Zn-containing Mg-6Gd-4Y-1Zn alloy consist of β-Mg matrix,Mg（24）（GdY）5 secondary phase and Mg（12）Y1Zn1 phase which has a 18R long period staking ordered（18R-LPSO）structure.After extrusion a 14H-LPSO phase is found in the Zn-containing alloy which is distributed between the 18R-LPSO strips in the as extruded microstructure.The formation mechanism of the 14H-LPSO phase is precipitation,and the reaction can be expressed as‘α-Mg′→α-Mg＋14H’.Zn content has no obvious effect on the precipitation ofβseries.Aged（T6 and T5 treatment）conducted on both the Mg-6Gd-4Y alloy and the Mg-6Gd-4Y-1Zn alloy causes the formation ofβ＇precipitates.The T6-aged Mg-6Gd-4Y-1Zn alloy exhibits high tensile strength combined with good ductility,and the values of the yield strength（YS）,ultimate tensile strength（UTS）and elongation are 309 MPa,438 MPa and 6.8%,respectively.It is due to the coexistence of 18R-LPSO phase and finely dispersed distribution of the 14H-LPSO phase and theβ＇precipitates in the microstructure.

关 键 词：镁合金 长周期结构(LPSO) 热挤压 时效处理 拉伸强度 

分 类 号：TG146.22[一般工业技术—材料科学与工程]