时效时间对7075-T6铝合金组织与性能的影响  

Effect of aging time on microstructure and properties of 7075-T6 aluminum alloy

作　　者：唐鹏 黄嘉良[1] 刘倩男 邓松云 Tang Peng;Huang Jialiang;Liu Qiannan;Deng Songyun(School of Resources,Environment and Materials,Guangxi University,Nanning Guangxi 530003,China;Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology,Guangxi University,Nanning Guangxi 530004,China;State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures,Guangxi University,Nanning Guangxi 530004,China;Guangxi Alnan Institute of Aerospace Transit Aluminum Alloy and Application,Nanning Guangxi 530031,China)

机构地区：[1]广西大学资源环境与材料学院,广西南宁530003 [2]广西大学广西石化资源加工及过程强化技术重点实验室,广西南宁530004 [3]广西大学省部共建特色金属材料与组合结构全寿命安全国家重点实验室,广西南宁530004 [4]广西南南铝航空交通铝合金新材料与应用研究院,广西南宁530031

出　　处：《金属热处理》2023年第7期131-137,共7页Heat Treatment of Metals

基　　金：国家自然科学基金(52261024);中国博士后科学基金(2021M693800);广西自然科学基金(2023GXNSFAA026374);广西石化资源加工与过程强化技术重点实验室开放项目(2022K005);广西大学大学生创新创业训练计划(202110593100);南宁市优秀青年科技创新创业人才培育计划(RC20190105)。

摘　　要：通过硬度测试、拉伸、导电率测试等方法,并借助金相显微镜、X衍射分析仪和扫描电镜等手段,系统研究时效时间对7075-T6铝合金组织和性能的影响。结果表明,随着时效时间的延长,7075-T6铝合金组织出现显著变化,时效18 h后晶粒尺寸由初始状态的88.76μm细化为35.78μm,时效24 h后粗化为67.88μm。7075-T6铝合金的硬度和导电率随着时效时间的延长出现了上升的趋势,分别在时效4 h和24 h时出现极大值。由微观组织变化可见,时效时间的延长会使合金G.P.区减少和η′(MgZn_(2))相增多,而G.P.区和η′相均可阻碍位错运动,使得合金的强度和导电率提升。当时效时间过长,出现过时效,晶粒再度粗化,合金的力学性能降低。Effect of aging time on microstructure and properties of 7075-T6 aluminum alloy were systematically studied by means of hardness test,tensile test,conductivity test,metallography microscope,X-ray diffractometer and scanning electron microscope.The results show that the microstructure of the 7075-T6 aluminum alloy changes significantly with the extension of aging time.The grain size is refined from 88.76 μm of the original state(0 h) to 35.78 μm after aging for 18 h,and then coarsened to 67.88 μm after aging for 24 h.The hardness and conductivity of the 7075-T6 aluminum alloy increase with the extension of aging time,and the maximum values appear when aging for 4 h and 24 h,respectively.It can be seen from the microstructure evolution that the increase of aging time will reduce the G.P.zone and increase the η′(MgZn_2) phase,while both the η′phase and the G.P.zone can inhibit the dislocation movement,and improve the strength and conductivity of the alloy.When the aging time is too long,the overaging occurs,the grains coarsen again,and the mechanical properties of the alloy are reduced.

关 键 词：7075-T6铝合金 时效时间 微观组织 力学性能 过时效 

分 类 号：TG161[金属学及工艺—热处理]