淬火速率对Al-Zn-Mg-Cu-Cr合金挤压棒材组织及硬度的影响  

Effect of Quenching Rate on Microstructure and Hardness of Al-Zn-Mg-Cu-Cr Alloy Extruded Bar

作　　者：韩素琦 刘胜胆[1,2,3] 李承波[1,2,3] 雷越[1,2,3] 邓运来[1,2,3] 张新明[1,2,3] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学有色金属材料与工程教育部重点实验室,长沙410083 [3]中南大学有色金属先进结构材料与制造协同创新中心,长沙410083

出　　处：《材料工程》2017年第4期9-14,共6页Journal of Materials Engineering

基　　金：国家重点基础研究计划项目(2012CB619501);国际科技合作专项项目(2013DFG51890);中南大学升华育英计划(20130603);国家科技部重点研发计划项目(2016YFB0300901)

摘　　要：通过硬度测试、扫描电镜、透射电镜研究淬火速率对Al-Zn-Mg-Cu-Cr合金挤压棒材组织及硬度的影响。结果表明:淬火速率低于100℃/s时,硬度开始明显下降;2℃/s淬火时,硬度下降了43%。淬火速率低于100℃/s时,随着淬火速率降低,冷却过程中(亚)晶界及晶内弥散粒子处非均匀形核析出η平衡相的数量和尺寸明显增加,时效强化效果明显降低。相同淬火速率时,晶内η平衡相尺寸大于晶界η平衡相尺寸。在所研究的淬火速率范围内建立起硬度值与η平衡相面积分数间的定量关系。The effect of quenching rate on microstructure and hardness of Al-Zn-Mg-Cu-Cr alloy extruded bar was studied by hardness test,scanning electron microscopy and transmission electron microscopy.The results show that at quenching rate below 100℃/s,during the cooling process,the hardness begins to fall significantly;and it decreases by 43%at the quenching rate of 2℃/s.At quenching rate below 100℃/s,the number and size of equilibriumηphase heterogeneously nucleated at(sub)grain boundaries and on dispersoids inside grains increase obviously with the decrease of quenching rate,leading to greatly reduced age-hardening response.At the same quenching rate,the equilibriumηphase inside grains is larger than that at grain boundaries.In the range of the studied quenching rates,aquantitative relationship between hardness and equilibriumηphase area fraction has been established.

关 键 词：Al-Zn-Mg-Cu-Cr合金 淬火速率 微观组织 硬度 

分 类 号：TG146.21[一般工业技术—材料科学与工程]