Al3Zr弥散相对铝锌镁合金板材微观组织及强度的影响  

Effect of Al3Zr Dispersoids on Microstructure and Strength of Al-Zn-Mg Alloy Sheets

作　　者：高靖靖 石大鹏 程全士 关悦 李影 柯书忠 陈景超[3,4] 刘胜胆[3,4] 叶凌英[3,4] GAO Jing-jing;SHI Da-peng;CHENG Quan-shi;GUAN Yue;LI Ying;KE Shu-zhong;CHEN Jing-chao;LIU Sheng-dan;YE Ling-ying(Henan Key Laboratory of Fastening Connection Technology,Xinyang 464000,Henan,China;Henan Aerospace Precision Machining Co Ltd,Xinyang 464000,Henan,China;School of Material Science and Engineering,Central South University,Changsha 410083,Hunan,China;Key Laboratory of Non-ferrous Metal Materials Science and Engineering,Ministry of Education,Central South University,Changsha 410083,Hunan,China)

机构地区：[1]河南省紧固连接技术重点实验室,河南信阳464000 [2]河南航天精工制造有限公司,河南信阳464000 [3]中南大学材料科学与工程学院,湖南长沙410083 [4]中南大学有色金属材料科学与工程教育重点实验室,湖南长沙410083

出　　处：《矿冶工程》2022年第6期173-177,182,共6页Mining and Metallurgical Engineering

基　　金：河南省紧固连接技术重点实验室开放课题(JGLJ2103)。

摘　　要：采用室温拉伸测试,结合金相显微镜、背散射电子衍射、透射电子显微镜、扫描透射电子显微镜等表征手段,研究了在Al-4.4Zn-1.2Mg合金板材中引入共格Al3Zr弥散相对其微观组织及强度的影响机理。Al3Zr弥散相抑制了再结晶,基于含Zr合金热轧板材中再结晶驱动力和Al3Zr弥散相钉扎晶界阻力,通过理论计算,预测了再结晶分数为45%,这与实验值40%相符。Al3Zr弥散相提高了淬火态和时效态板材的强度。Al3Zr弥散相平均尺寸约22.3nm,通过奥罗万机制阻碍位错运动,引起强度增加值为43.3 MPa,抑制再结晶的附加强化效果为12.6 MPa。含Zr合金板材中的晶界和亚晶界数量更多,时效时在合金中形成了更多无强化作用的η相,减少了η′沉淀强化相的数量,沉淀强化作用引起的强度增加量较无Zr合金的低32.4 MPa。Al3Zr dispersoids were introduced to Al-4.4 Zn-1.2 Mg alloy sheets, and their effects on microstructure and strength were investigated by means of tensile test at room temperature, optical microscopy, electron back scattered diffraction, transmission electron microscopy and scanning transmission electron microscopy. Al3Zr dispersoids inhibited recrystallization. Based on the driving force of recrystallization and retarding effect of Al3Zr dispersoids on grain boundary migration in Zr-containing alloy sheet, the recrystallization fraction was calculated to be 45%, which was almost equal to 40% of the experimental result. The presence of coherent Al3Zr dispersoids increased the strength of the as-quenched and aged sheets. Al3Zr dispersoids with an average size of about 22.3 nm inhibited dislocations due to Orowan strengthening, leading to an increment of about 43.3 MPa in the strength, and the recrystallization inhibition brought an additional increment of about 12.6 MPa. In the Zr-containing alloy sheet, there were a larger amount of grain boundaries and sub-grain boundaries, leading to more formation of η phase with little hardening effect, which decreased the quantity of η′ hardening phase after aging. As a result, the increment in its strength brought by precipitation hardening was 32.4 MPa lower compared to the Zr-free alloy sheet.

关 键 词：AL-ZN-MG合金 强度 弥散相 再结晶 微合金化 锆 AL3ZR 

分 类 号：TG146.2[一般工业技术—材料科学与工程]