Effects of minor Sc and Zr additions on mechanical properties and microstructure evolution of Al−Zn−Mg−Cu alloys  

添加微量Sc和Zr对Al-Zn-Mg-Cu合金力学性能和显微组织演变的影响

作　　者：Quan-feng XIAO Ji-wu HUANG Ying-ge JIANG Fu-qin JIANG Yun-feng WU Guo-fu XU 肖权峰;黄继武;蒋莺歌;江福清;吴昀峰;徐国富(中南大学材料科学与工程学院,长沙410083;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)

机构地区：[1]School of Materials Science and Engineering,Central South University,Changsha 410083,China [2]Key Laboratory of Nonferrous Metallic Materials Science and Engineering,Ministry of Education,Central South University,Changsha 410083,China

出　　处：《Transactions of Nonferrous Metals Society of China》2020年第6期1429-1438,共10页中国有色金属学报（英文版）

基　　金：Project (2016B090931004) supported by the Scientific and Research Plan of Guangdong Province, China;Project (51601229) supported by the National Natural Science Foundation of China。

摘　　要：The effects of minor Sc and Zr additions on the mechanical properties and microstructure evolution of Al Zn Mg Cu alloys were studied using tensile tests, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The ultimate tensile strength of the peak-aged Al Zn Mg Cu alloy is improved by about 105 MPa with the addition of 0.10% Zr. An increase of about 133 MPa is observed with the joint addition of 0.07% Sc and 0.07% Zr. For the alloys modified with the minor addition of Sc and Zr (0.14%), the main strengthening mechanisms of minor addition of Sc and Zr are fine-grain strengthening, sub-structure strengthening and the Orowan strengthening mechanism produced by the Al3(Sc,Zr) and Al3Zr dispersoids. The volume of Al3Zr particles is less than that of Al3(Sc,Zr) particles, but the distribution of Al3(Sc,Zr) particles is more dispersed throughout the matrix leading to pinning the dislocations motion and restraining the recrystallization more effectively.采用拉伸试验、扫描电镜和透射电镜,研究添加微量Sc和Zr对Al-Zn-Mg-Cu合金力学性能和显微组织演变的影响。添加0.10%Zr使合金的抗拉强度提高约105 MPa,而复合添加0.07%Sc和0.07%Zr使合金抗拉强度提高约133 MPa。在峰时效状态的合金中,添加微量Sc和Zr的主要强化机制是Al3(Sc,Zr)和Al3Zr粒子引起的细晶强化、亚晶强化和奥罗万强化。Al3(Sc,Zr)颗粒的尺寸大于Al3Zr颗粒的尺寸,但Al3(Sc,Zr)粒子分布更加弥散,因此,Al3(Sc,Zr)粒子能更加有效钉扎位错运动和抑制再结晶。

关 键 词：Al Zn Mg Cu alloys Al3(Sc Zr) AL3ZR dislocation motion recrystallization strengthening mechanism 

分 类 号：TG146.21[一般工业技术—材料科学与工程]