铜元素含量对超高强铝合金力学性能淬火敏感性的影响  

Effect of Cu content on quenching sensitivity relative to mechanical properties of ultra-high strength aluminum alloy

作　　者：张梦晗 刘胜胆[1,2,3] 蒋靖宇 马志民[5] 韦卫昌 ZHANG Meng-han;LIU Sheng-dan;JIANG Jing-yu;MA Zhi-min;WEI Wei-chang(School of Materials Science and Engineering,Central South University,Changsha 410083,China;National Key Laboratory of Science and Technology on High-strength Structural Materials,Central South University,Changsha 410083,China;Key Laboratory of Non-Ferrous Metal Materials Science and Engineering,Ministry of Education,Central South University,Changsha 410083,China;School of Metallurgy and Environment,Central South University,Changsha 410083,China;Baotou Vocational&Technical College,Baotou 014030,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学轻质高强结构材料重点实验室,长沙410083 [3]中南大学有色金属材料科学与工程教育部重点实验室,长沙410083 [4]中南大学冶金与环境学院,长沙410083 [5]包头职业技术学院,包头014030

出　　处：《中国有色金属学报》2023年第3期715-728,共14页The Chinese Journal of Nonferrous Metals

基　　金：国家重点研发计划资助项目(2016YFB0300901)。

摘　　要：采用浸入式末端淬火的方法,结合硬度、电导率测试和相图、连续冷却转变曲线计算,通过电子背散射衍射分析、扫描电子显微镜和透射电子显微镜等微观组织表征方法,研究铜元素含量对超高强AlZn-Mg-Cu合金力学性能淬火敏感性的影响。结果表明:淬火速率从400℃/s降低至70℃/s时,铜含量几乎不影响合金的淬火敏感性;淬火速率从70℃/s降低至4℃/s时,随着铜含量增加,析出驱动力增大,淬火析出相的种类和数量增多、尺寸增大,消耗的相对溶质原子数量增多,合金的淬火敏感性也随之提高;根据晶界及晶内淬火析出相的面积分数差异,发现晶内淬火析出相的数量差异是造成不同合金淬火敏感性差异的主要因素。The effect of Cu content on quenching sensitivity relative to mechanical properties of ultra-high strength Al-Zn-Mg-Cu alloy was investigated by immersion end-quenching test,hardness test,conductivity test,phase diagram calculation,continuous cooling transformation curve calculation,electron backscattered diffraction,scanning electron microscopy,transmission electron microscopy.As quenching rate decreases from 400°C/s to 70°C/s,Cu content has little effect on quenching sensitivity.However,when the quenching rate decreases from 70°C/s to 4°C/s,with the increase of Cu content,the driving force for precipitation increases significantly.As a result,the types,number and size of quenching-induced phase increase,and more solute atoms are consumed,leading to the increase of quenching sensitivity.According to the proportion of quenching-induced phase at(sub)grain boundaries and in the interior of grains,the contribution of them to quenching sensitivity was analyzed.The difference in the number of quenching-induced phase in the interior of grains is the main factor that causes the difference in quenching sensitivity of alloys with different Cu contents.

关 键 词：AL-ZN-MG-CU合金 CU含量 淬火析出相 硬度 淬火敏感性 

分 类 号：TG146.2[一般工业技术—材料科学与工程]