w(Zn)/w(Mg)对Al-Zn-Mg合金组织和力学性能的影响  

Effect of w(Zn)/w(Mg)ratio on microstructure and mechanical properties of Al-Zn-Mg alloy

作　　者：林鹏 王建军 邓运来[2] LIN Peng;WANG Jianjun;DENG Yunlai(CRRC Qingdao Sifang Co.,Ltd.,Qingdao 266111,China;School of Materials Science and Engineering,Central South University,Changsha 410083,China)

机构地区：[1]中车青岛四方机车车辆股份有限公司,山东青岛266111 [2]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《轻合金加工技术》2023年第11期26-32,共7页Light Alloy Fabrication Technology

基　　金：中国国家铁路集团有限公司科技研究开发计划(K2021J040)。

摘　　要：借助金相显微镜(OM)、透射电子显微镜(TEM)、维氏硬度计和电子万能试验机研究了w(Zn)/w(Mg)对新型Al-Zn-Mg合金组织和力学性能的影响。研究结果表明:当Zn、Mg总含量相近时,w(Zn)/w(Mg)降低,则Al-Zn-Mg合金的硬度提高,峰值时效时间缩短。当Zn、Mg总量减少,且w(Zn)/w(Mg)减小时,意味着合金中Mg含量相对较高,这同样提高了合金的峰值硬度,缩短了峰值时效时间。随着w(Zn)/w(Mg)从11.4降至6.1,合金晶内η′相数量密度增大,平均直径减小,η′相数量密度从66521μm^(-3)增加至118142μm^(-3),平均直径从4.3 nm降低至3.7 nm,合金的拉伸强度随之提高。当w(Zn)/w(Mg)为6.1时,合金T6态的抗拉强度、屈服强度和断后伸长率分别为447 MPa、397 MPa和18.9%。The effect of w(Zn)/w(Mg)on microstructure and mechanical properties of Al-Zn-Mg alloy was investigated by optical metalloscope(OM),transmission electron micro-scope(TEM),Vickers hardness tester and electronic universal testing machine.The results show that when the w(Zn+Mg)is similar,w(Zn)/w(Mg)decrease,then the hardness of Al-Zn-Mg alloy improves and the peak aging time shorten.When w(Zn+Mg)decreases and w(Zn)/w(Mg)decreases,the content of Mg in the alloy is relatively high,which also im-proves the peak hardness of the alloy and shortens the peak aging time.With w(Zn)/w(Mg)decreasing from 11.4 to 6.1,the number density of η′phases increases and the average diameter of η′phases decreases.The number density of η′phases increases from 66521μm^(-3) to 118142μm^(-3),and the average diameter of η′phases decreases from 4.3 nm to 3.7 nm,and the tensile strength of the alloy increases accordingly.When w(Zn)/w(Mg)is 6.1,the ultimate tensile strength,yield strength and elongation of T6 alloy are 447 MPa,397 MPa and 18.9%,respectively.

关 键 词：AL-ZN-MG合金 w(Zn)/w(Mg) 显微组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]