摘要
通过Kahn撕裂试验,研究微量Mn元素的添加对Al-Zn-Mg-Zr合金板材断裂韧性的影响,并结合扫描电镜(SEM)、电子背散射衍射技术(EBSD)、透射电镜(TEM)和扫描透射电镜(STEM)等显微组织表征结果对影响机理进行分析和讨论。研究结果表明:在Al-Zn-Mg-Zr板材中添加微量Mn元素可以提高其断裂韧性,撕裂强度从550.9MPa增至581.5MPa,单位面积裂纹形核功从168.6N/mm增至235.4N/mm,断裂方式从沿晶断裂为主转变为穿晶韧窝型断裂。Mn元素增加了板材的再结晶分数和残留第二相的面积分数,引入了亚微米级含Mn弥散相,增加了Al3Zr弥散相的尺寸和间距,减少了晶内η'强化相的数量,降低了晶界η相的面积分数,增大了其间距。
The effect of minor Mn addition on fracture toughness of Al-Zn-Mg-Zr alloy sheet was studied by means of Kahn tear test,scanning electron microscopy(SEM),electron back scattering diffraction(EBSD)technique,transmission electron microscopy(TEM)and scanning transmission electron microscopy(STEM).The results show that the fracture toughness is significantly improved due to the addition of Mn to Al-Zn-Mg-Zr sheet.The tear strength increases from 550.9 MPa to 581.5 MPa and the unit initiation energy increases from168.6 N/mm to 235.4 N/mm,and the mode of fracture changes from intergranular fracture to transgranular dimple fracture.The addition of Mn increases the recrystallization fraction and area fraction of residual second phase in the sheet,and leads to the submicron Mn-dispersoids.It also increases the size and spacing of Al3Zr dispersoids,and reduces the number ofη’strengthening phase and the area fraction ofηphase at the grain boundary and enlarges its spacing.
作者
陈景超
柴文茹
汪庆
杨臻珅
刘胜胆
叶凌英
唐建国
CHEN Jingchao;CHAI Wenru;WANG Qing;YANG Zhenshen;LIU Shengdan;YE Lingying;TANG Jianguo(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Key Laboratory of Nonferrous Materials Science and Engineering,Ministry of Education,Central South University,Changsha 410083,China;Nonferrous Metal Oriented Advanced Structural Materials and Manufacturing Cooperative Innovation Center,Central South University,Changsha 410083,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2019年第12期2948-2957,共10页
Journal of Central South University:Science and Technology
基金
国家重点研发计划(2016YFB0300901)::湖南省重大科技专项(2016GK1004)::中南大学升华育英计划项目(20130603)~~
