Suppression of discontinuous precipitation and strength improvement by Sc doping in Cu-6 wt%Ag alloys  

作　　者：Bailing An Rongmei Niu Yan Xin William LStarch Zhaolong Xiang Yifeng Su Robert E.Goddard Jun Lu Theo M.Siegrist Engang Wang Ke Han 

机构地区：[1]Key Laboratory of Electromagnetic Processing of Materials(Ministry of Education),Northeastern University,Shenyang 110819,China [2]School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China [3]School of Metallurgy,Northeastern University,Shenyang 110819,China [4]National High Magnetic Field Laboratory,Florida State University,Tallahassee,FL 32310,USA [5]Oak Ridge National Laboratory,Oak Ridge,TN 37830,USA [6]FAMU-FSU College of Engineering,Tallahassee,FL 32310,USA

出　　处：《Journal of Materials Science & Technology》2023年第4期80-96,共17页材料科学技术（英文版）

基　　金：This work was supported by the National Key R&D Program of China(No.2017YFE0107900);the 111 Project(2.0)of China(No.BP0719037);Some work was performed at the National High Magnetic Field Laboratory,USA,which is supported by the National Science Foundation Cooperative Agreement(Nos.DMR-1157490 and NSF DMR-1644779)and the State of Florida,USA.The authors are grateful to Mary Tyler for editing.The authors are grateful to China Scholarship Council(CSC)for financial support.

摘　　要：In low-Ag Cu matrix alloys,the presence of coarse discontinuous precipitates may limit strength.We demonstrated that discontinuous precipitation was suppressed,and continuous precipitation was en-hanced by the doping of Cu-6 wt%Ag with Sc.A high-volume fraction of continuous precipitates,which nucleated on{111}planes,led to a 55 MPa increase in strength,with only a slight decrease in electri-cal conductivity.The addition of Sc inhibited the nucleation of discontinuous precipitates by causing the Sc and the Ag to co-segregate onto grain boundaries,thus forming a thin intermetallic compound layer between grains.After deformation,both discontinuous and continuous precipitates were drawn into Ag fibers.The combination of deformation strain and doping caused an increase in density and a decrease in the diameter of Ag fibers,resulting in about 205 MPa increase in doped samples when the deformation strain reached 4.9.The thinner,denser Ag fibers in the doped samples also caused higher electron scatter-ing at interfaces,leading to electrical conductivity that was 11%IACS lower than in non-doped samples.For reference,100%IACS(International Annealed Copper Standard)is equivalent to 1.7241μΩcm.

关 键 词：Sc doping Grain boundary segregation Precipitation STRENGTH Electrical conductivity Plastic deformation 

分 类 号：TG146.11[一般工业技术—材料科学与工程]