Grain refinement is a well-recognized method to simultaneously increase the strength and ductility of metallic materials.Fabrication of ultrafine-grained metals in bulk using a simple low-cost approach is a long-term goal for material scientists.In this work,based on the chemical composition of a biomedical Ti-15Zr alloy,a series of novel Ti-15Zr-xCu(x=0,3,5,7 wt.％)alloys were designed and fabricated.The alloys were quenched in the single β phase region to obtain a martensitic microstructure and deformed in the temperature range of 710-750℃to obtain an ultrafine-grained microstructure through marten-site decomposition under thermomechanical coupling conditions.Experimental results showed that Cu alloying could increase the dynamic recrystallization(DRX)nucleation rate due to its role in both re-fining martensitic lath width and increasing dislocation density.Cu alloying could also suppress grain growth due to the precipitated Ti2Cu particles exerting pinning forces on the grain boundaries.The op-timal Cu content in the Ti-15Zr-xCu alloy was determined to be 5 wt.％.After being subjected to a com-pression leading to a 70％height reduction at 730℃and 1 s-1,the grain size of the Ti-15Zr-5Cu alloy was only 180±70 nm.The tensile strength of the as-prepared alloy reached 975±10 MPa,which was 45％higher than that of the conventional Ti-15Zr alloy(673±16 MPa).This increase in strength was achieved without any reduction in ductility.The comprehensive mechanical properties of the ultrafine-grained Ti-15Zr-5Cu alloy are better than that of the Roxolid Ti-Zr alloy currently used for dental implants.

Wenwei Gao;Hai Wang;Konrad Koenigsmann;Shuyuan Zhang;Ling Ren;Ke Yang

Shi-changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China;University of Chicago,Chicago,IL 60637,USA

材料科学技术（英文版）

[1]Wenwei Gao;Hai Wang;Konrad Koenigsmann;Shuyuan Zhang;Ling Ren;Ke Yang-.Fabrication of ultrafine-grained Ti-15Zr-xCu alloys through martensite decompositions under thermomechanical coupling conditions)[J].材料科学技术（英文版）,2022(32):19-28

marten,Roxolid

Fabrication,ultrafine,grained,15Zr,xCu,alloys,through,martensite,decompositions,under,thermomechanical,coupling,conditions,Grain,refinement,well,recognized,method,simultaneously,increase,strength,ductility,metallic,materials,metals,bulk,using,simple,low,cost,approach,long,goal,scientists,In,this,work,chemical,biomedical,series,novel,were,designed,fabricated,quenched,single,phase,region,obtain,martensitic,microstructure,deformed,temperature,range,Experimental,results,showed,that,alloying,could,dynamic,recrystallization,DRX,nucleation,rate,due,its,role,both,fining,lath,width,increasing,dislocation,density,also,suppress,growth,precipitated,Ti2Cu,particles,exerting,pinning,forces,boundaries,timal,content,was,determined,After,being,subjected,pression,leading,height,reduction,size,5Cu,only,tensile,prepared,reached,which,higher,than,conventional,This,achieved,without,any,comprehensive,properties,better,currently,used,dental,implants

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