Al-Mg-Zn-Cu合金时效过程中的显微组织、力学性能及其强化机制  

Microstructure,mechanical properties and strengthening mechanism of Al-Mg-Zn-Cu alloy during aging process

作　　者：沈顾伟 陈小林 闫捷 范龙毅 杨洲 张晋 杨大龙[1,2] 管仁国 SHEN Gu-wei;CHEN Xiao-lin;YAN Jie;FAN Long-yi;YANG Zhou;ZHANG Jin;YANG Da-long;GUAN Ren-guo(Key Laboratory of Near-Net Forming of Light Metals of Liaoning Province,Dalian Jiaotong University,Dalian 116028,China;Engineering Research Center of Continuous Extrusion,Ministry of Education,Dalian Jiaotong University,Dalian 116028,China;Songshan Lake Materials Laboratory,Dongguan 523808,China)

机构地区：[1]大连交通大学辽宁省轻质金属材料近净成形重点实验室,大连116028 [2]大连交通大学连续挤压教育部工程研究中心,大连116028 [3]松山湖材料实验室,东莞523808

出　　处：《中国有色金属学报》2023年第12期4002-4012,共11页The Chinese Journal of Nonferrous Metals

基　　金：国家重点研发计划资助项目(2022YEE0137900);大连市高层次人才创新支持计划资助项目(2021RD06)。

摘　　要：新型T-Mg_(32)(Al,Zn,Cu)_(49)相强化的Al-Mg-Zn-Cu合金表现出优异的力学性能,本文以Al-4.39Mg-2.78Zn-0.42Cu合金为研究对象,对合金时效过程中的显微组织和力学性能进行研究,并揭示Al-Mg-Zn-Cu合金的强化机制。结果表明:随着第二阶段140℃时效时间的增加,合金的显微组织由尺寸细小的Guinier-Preston(GP)区逐渐析出T相,析出相的尺寸不断增大,数量密度逐渐降低。拉伸测试结果表明:时效过程中合金的强度先升高后降低;在峰时效(90℃,48 h)+(140℃,16 h)状态下,合金的屈服强度为338 MPa。强化机制分析表明:T相析出强化以及Mg溶质原子的固溶强化和细晶强化分别对合金屈服强度贡献了284.8 MPa、55.6 MPa、12.2 MPa,说明了Al-Mg-Zn-Cu合金的主要强化机制为析出强化。The novel Al-Mg-Zn-Cu alloy reinforced by T-Mg_(32)(Al,Zn,Cu)_(49)phase exhibits excellent mechanical properties.In this paper,microstructure and mechanical properties during aging process were investigated.Meanwhile,the strengthening mechanism of Al-Mg-Zn-Cu alloy was elucidated.The results show that,with the increase of aging time at 140℃,T-phase is gradually precipitated from GP zone with fine size.The size of precipitates keeps increasing and the number density keeps decreasing.The tensile test results show that,during the aging treatment,the strength of this alloy increases and then decreases,and the yield strength is 338 MPa at peak aging state(90℃,48 h)+(140℃,16 h).According to the calculation results of strengthening mechanism,precipitation strengthening of T-phase,solid solution strengthening of Mg solute atom,and grain boundary strengthening provide 284.8 MPa,55.6 MPa and 12.2 MPa,respectively,to the yield strength of alloy.This strongly proves that the main strengthening mechanism of Al-Mg-Zn-Cu alloy is precipitation strengthening.

关 键 词：Al-Mg-Zn-Cu合金 力学性能 析出行为 强化机制 

分 类 号：TG146.2[一般工业技术—材料科学与工程]