CoCrFeNi high entropy alloy(HEA)has attracted extensive attention due to its excellent corrosion re-sistance,but the low strength limits its engineering application prospects.In order to develop CoCrFeNi based HEAs with high strength,ductility and corrosion resistance,the effects of Zr content on the mi-crostructure,mechanical properties and corrosion resistance of heterogeneous CoCrFeNiZrx(x=0,0.25,0.5 and 1)HEAs were investigated in this work.The results indicate that the increase of Zr content can significantly affect the phase stability of the alloy,and promote the formation of intermetallic compounds(Ni7Zr2 and/or Laves phase)and the transformation of solid solution from face-centered cubic(FCC)struc-ture(x=0,0.25 and 0.5)to body-centered cubic(BCC)structure(x=1).Reasonable control of the Zr content can endow the alloy excellent comprehensive properties.Especially,for CoCrFeNiZr0.25 alloy,com-posed of FCC matrix and a small amount of Ni7Zr2 phases,the yield strength(～655 MPa)is increased by nearly four times higher than that of Zr-free alloy,and it also has good ductility(fracture stain＞50％).Meanwhile,the corrosion resistance of CoCrFeNiZr0.25 alloy is better than that of SS304.The EIS results show that the addition of Zr reduces the stability of the passive film on the alloy,which can be related to the content of the beneficial oxide in the passive film and the thickness of the passive film through XPS analysis.Moreover,the work functions of different phases in CoCrFeNiZrx alloys were obtained by first-principles calculations,which further confirmed the selective corrosion mechanism of the CoCrFeNiZrx alloy combining the experimental results.

Wu Qi;Wenrui Wang;Xiao Yang;Lu Xie;Jiaming Zhang;Dongyue Li;Yong Zhang

School of Mechanical Engineering,University of Science and Technology Beijing,Beijing 100083,China;Key Laboratory of Fluid Interaction with Material,Ministry of Education,Beijing 100083,China;Key Laboratory of Cryogenics,Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China;State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China

材料科学技术（英文版）

[1]Wu Qi;Wenrui Wang;Xiao Yang;Lu Xie;Jiaming Zhang;Dongyue Li;Yong Zhang-.Effect of Zr on phase separation,mechanical and corrosion behavior of heterogeneous CoCrFeNiZrx high-etropy alloy)[J].材料科学技术（英文版）,2022(14):76-85

CoCrFeNiZrx,etropy,crostructure,Ni7Zr2,CoCrFeNiZr0

Effect,separation,mechanical,corrosion,behavior,heterogeneous,entropy,attracted,extensive,attention,due,excellent,but,low,strength,limits,engineering,application,prospects,In,order,develop,HEAs,ductility,resistance,effects,content,properties,were,investigated,this,work,results,indicate,that,significantly,affect,stability,promote,intermetallic,compounds,Laves,transformation,solid,solution,from,face,centered,cubic,FCC,body,BCC,Reasonable,control,endow,comprehensive,Especially,posed,matrix,small,amount,phases,yield,increased,by,nearly,four,times,higher,than,free,also,good,fracture,stain,Meanwhile,better,SS304,EIS,show,addition,reduces,passive,film,which,related,beneficial,oxide,thickness,through,XPS,analysis,Moreover,functions,different,alloys,obtained,first,principles,calculations,further,confirmed,selective,mechanism,combining,experimental

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