High density alloys with enhanced deformability and strength are urgently required in energy,military and nuclear industries,etc.In this work,we present a new kind of NiCoFeCrMoW high entropy alloys(HEAs)which possess higher densities and sound velocities than copper.We systematically investigate the phase structure,quasi-static tensile,dynamic compression and related deformation mechanism of these HEAs.It is shown that single FCC or FCC+μ dual phases were formed in the HEAs depending on Mo and W content and annealing temperature.Excellent quasi-static tensile and dynamic compres-sion properties have been achieved for these HEAs,e.g.Ni30Co30Fe21Cr10Wg HEA annealed at 1573 K exhibited a yield and ultimate tensile strength and elongation of～364 MPa,～866 MPa and～32％,re-spectively,in quasi-static test;a yield strength of～710 MPa and no fracture under the dynamic strain rate of 4100 s-1.Superior strain rate sensitivity(SRS)of yield strength than that of previously reported FCC HEAs have been evidenced.The dynamic stress-strain constitutive relation can be described by the modified Johnson-Cook model.As for the dynamic deformation mechanism,it is envisaged that the reg-ulation of stacking fault energy and Peierls barrier in current HEAs resulted in occurrences of abundant nanoscale deformation twins and microbands during high strain rate compression.The synergistic mi-crobanding and twinning effectively contributes to the enhanced dynamic deformability and strengthen-ing effect.Besides,the interactions of dislocations with precipitates,stacking faults(SFs)with twins,and between SFs also contribute to extraordinary work-hardening capacity.

Xuli Liu;Yidong Wu;Yansong Wang;Jinbin Chen;Rui Bai;Lei Gao;Zhe Xu;William Yi Wang;Chengwen Tan;Xidong Hui

State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China;School of Materials Science and Engineering,Beijing Institute of Technology,Beijing 100081,China;State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China

材料科学技术（英文版）

[1]Xuli Liu;Yidong Wu;Yansong Wang;Jinbin Chen;Rui Bai;Lei Gao;Zhe Xu;William Yi Wang;Chengwen Tan;Xidong Hui-.Enhanced dynamic deformability and strengthening effect via twinning and microbanding in high density NiCoFeCrMoW high-entropy alloys)[J].材料科学技术（英文版）,2022(32):164-176

microbanding,NiCoFeCrMoW,FCC+,Ni30Co30Fe21Cr10Wg,Peierls,microbands,crobanding

Enhanced,dynamic,deformability,strengthening,via,twinning,density,entropy,alloys,High,enhanced,are,urgently,required,energy,military,nuclear,industries,etc,In,this,work,present,new,kind,HEAs,which,possess,higher,densities,sound,velocities,than,copper,We,systematically,investigate,structure,quasi,static,tensile,compression,related,deformation,mechanism,these,It,shown,that,single,dual,phases,were,formed,depending,content,annealing,temperature,Excellent,properties,have,been,achieved,annealed,exhibited,yield,ultimate,elongation,spectively,test,fracture,under,strain,rate,Superior,sensitivity,SRS,previously,reported,evidenced,stress,constitutive,relation,can,described,by,modified,Johnson,Cook,model,envisaged,reg,ulation,stacking,barrier,current,resulted,occurrences,abundant,nanoscale,twins,during,synergistic,effectively,contributes,Besides,interactions,dislocations,precipitates,faults,SFs,between,also,extraordinary,hardening,capacity

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