Grain refinement usually makes the materials stronger,while ductility has a dramatic loss.Here,a su-perior tensile strength-ductility synergy in a fully recrystallized ultrafine-grained(UFG)Al0.1CrFeCoNi with abundant annealing twins was achieved by cold rolling at room temperature and short-time anneal-ing.The microstructure characterization using electron backscattered scattering diffraction demonstrates that abundant geometrically necessary dislocations(GNDs)gather around the grain boundaries and twin boundaries after tensile deformation.Although coarse-grained(CG)samples undergo a larger plastic de-formation than UFG samples,the GND density decreases with grain size ranging from UFG to CG.Trans-mission electron microscopy results reveal that the annealing twin boundary,which effectively hinders the dislocation slip and stores dislocation in grain interior,and the activation of multiple deformation twins are responsible for the superior strength-ductility synergy and work hardening ability.In addition,the yield strength of fully recrystallized Al0.1CrFeCoNi follows a Hall-Petch relationship(σy=24+676 d-1/2),where d takes into account both grain boundaries and annealing twin boundaries.The strengthen-ing effects of grain boundaries and annealing twin boundaries were also evaluated separately.

Jiahao Li;Kejie Lu;Xiaojun Zhao;Xinkai Ma;Fuguo Li;Hongbo Pan;Jieming Chen

Key Laboratory of Advanced Technologies of Materials,Ministry of Education,School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China;Shenzhen Institute of Southwest Jiaotong University,Shenzhen 518000,China;State Key Laboratory of Solidification Processing,School of Materials Science and Engineering,Northwestern Polytechnical University,Xi'an 710072,China;Anhui Province Key Laboratory of Metallurgical Engineering& Resources Recycling(Anhui University of Technology),243002 Maanshan,China;Luoyang Ship Material Research Institute,Luoyang 471023,China

材料科学技术（英文版）

[1]Jiahao Li;Kejie Lu;Xiaojun Zhao;Xinkai Ma;Fuguo Li;Hongbo Pan;Jieming Chen-.A superior strength-ductility synergy of Al0.1CrFeCoNi high-entropy alloy with fully recrystallized ultrafine grains and annealing twins)[J].材料科学技术（英文版）,2022(36):185-194

1CrFeCoNi,perior,GNDs,24+676

superior,ductility,synergy,Al0,high,entropy,alloy,fully,recrystallized,ultrafine,grains,annealing,twins,Grain,refinement,usually,makes,materials,stronger,while,has,dramatic,loss,Here,tensile,grained,UFG,abundant,was,achieved,by,cold,rolling,room,temperature,short,microstructure,characterization,using,electron,backscattered,scattering,diffraction,demonstrates,that,geometrically,necessary,dislocations,gather,around,boundaries,after,deformation,Although,coarse,CG,samples,undergo,larger,plastic,than,density,decreases,size,ranging,from,Trans,mission,microscopy,results,reveal,boundary,which,effectively,hinders,slip,stores,interior,activation,multiple,are,responsible,work,hardening,ability,In,addition,yield,follows,Hall,Petch,relationship,where,takes,into,account,both,strengthen,effects,were,also,evaluated,separately

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