Strength and ductility enhancement of twin-roll cast Al-Zn-Mg-Cu alloys with high solidification intervals through a synergistic segregation-controlling strategy  

作　　者：Bing Lu Yong Li Wei Yu Haiyao Wang Yin Wang Zhaodong Wang Guangming Xu 

机构地区：[1]State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang 110819,China [2]Guangxi Advanced Aluminum Processing Innovation Center Co.LTD,Nanning 530007,China [3]Key Laboratory of Electromagnetic Processing of Materials,Ministry of Education,Northeastern University,Shenyang 110819,China

出　　处：《Journal of Materials Science & Technology》2023年第11期225-239,共15页材料科学技术（英文版）

基　　金：financially supported by the Major Program of National Natural Science Foundation of China(No.51790485);the Key Research and Development Project of Shandong Province(No.2019JZZY010401);Nanning Science and Technology Major Special Projects(No.20201041);State Key Laboratory of Rolling and Automation(RAL)of Northeastern University.

摘　　要：Center segregation and banded intergranular segregation(B-IGS)should be well controlled to improve the mechanical properties of twin-roll cast(TRC)aluminum alloys,especially for alloys with high solid-ification intervals.In the present work,a synergistic grain refinement strategy was designed using an Al-5Ti-B grain refiner and Ti,Zr,and Sc microalloying elements to simultaneously control center seg-regation and B-IGS in TRC Al-Zn-Mg-Cu alloys.As the grain size decreased,center segregation defects were eliminated and transformed into dispersed B-IGS defects;simultaneously,the width and length of the B-IGS were also reduced.Moreover,the macro-distributions of the alloying elements along the thickness direction became more homogeneous due to a weak shear-induced dilation effect.The well-controlled multiscale segregation improved the uniformity of the alloy macrostructure,accelerated the redissolution of the crystalline phase,dispersed the aggregated residual phase,and refined grains under the T6 state.Hence,the strength and ductility of the alloys under the T6 state were simultaneously improved,and the hardness distribution along the thickness direction became more homogenous.Furthermore,the underlying mechanisms of segregation evolution and strength and ductility enhancements were elucidated.This work provides a novel strategy to effectively control multiscale segregation and produce high-performance aluminum alloys with high solidification intervals by TRC.

关 键 词：Twin-roll casting Al-Zn-Mg-Cu alloy Center segregation Banded intergranular segregation Mechanical properties Grain refinement 

分 类 号：TG146.21[一般工业技术—材料科学与工程]