Hardness-thermal stability synergy in nanograined Ni and Ni alloys:Superposition of nanotwin and low-energy columnar boundary

作     者：F.H.Duan Y.Lin Q.Li J.H.Luan J.Lu J.Pan Y.Li F.H.Duan;Y.Lin;Q.Li;J.H.Luan;J.Lu;J.Pan;Y.Li

作者机构：Shenyang National Laboratory for Materials ScienceInstitute of Metal ResearchChinese Academy of SciencesShenyang 110016China Laboratory of Nanomaterials&NanomechanicsDepartment of Mechanical EngineeringCity University of Hong KongHong KongChina State Key Laboratory of Material Processing and Die&Mould Technology and School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Department of Materials Science and EngineeringCity University of Hong KongHong KongChina Centre for Advanced Structural MaterialsGreater Bay Joint DivisionShenyang National Laboratory for Materials ScienceCity University of Hong Kong Shenzhen Research InstituteShenzhen 518057China City U-Shenzhen Futian Research InstituteShenzhen 518045China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2023年第137卷第6期

页      面：123-131页

核心收录：

学科分类：07[理学] 08[工学] 070205[理学-凝聚态物理] 0806[工学-冶金工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0702[理学-物理学] 

基　　金：This work was supported by the National Natural Science Foundation of China(Nos.52022100,52001075,and 52101162) the Shenyang National Laboratory for Materials Science(No.E01SL102) J.Pan is also grateful for support from the Youth In-novation Promotion Association of the Chinese Academy of Sci-ences(No.2020194) Y.Li acknowledges financial support from the Shenyang National Laboratory for Materials Science.J.Lu gratefully acknowledges the support of the National Key R&D Program of China(No.2017YFA0204403) the Major Program of the National Natural Science Foundation of China(NSFC,No.51590892) the Hong Kong Collaborative Research Fund(CRF)Scheme(C4026-17W) Theme-Based Research Scheme(Ref.T13-402/17-N) Gen-eral Research Fund(GRF)Scheme(CityU 11247516,CityU 11209918,CityU 11216219) Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone Shenzhen Park Project(No.HZQB-KCZYB-2020030).Atom probe tomography research was conducted at the Inter-University 3D Atom Probe Tomography Unit of the City University of Hong Kong,which is supported by the CityU grant 9360161. 

主　　题：Nanotwin Thermal stability Hardness Low-angle grain boundary Microalloying 

摘      要：Refining grains into nanoscale can significantly strengthen and harden metallic materials;however,nanograined metals generally exhibit low thermal stability,hindering their practical applications.In this work,we exploit the superposition of the contribution of nanotwins,low-angle grain boundaries,and microalloying to tailor superior combinations of high hardness and good thermal stability in Ni and Ni alloys.For the nanotwinned Ni having a twin thickness of∼2.9 nm and grain size of 28 nm,it exhibits a hardness over 8.0 GPa and an onset coarsening temperature of 623 K,both of which are well above those of nanograined Ni.Re/Mo microalloying can further improve the onset coarsening temperature to 773 K without comprising hardness.Our analyses reveal that high hardness is achieved via strengthen-ing offered by extremely fine nanotwins.Meanwhile,the superior thermal stability is mainly ascribed to the low driving force for grain growth induced by the low-angle columnar boundary architecture and to the additional pinning effect on the migration of twin/columnar boundaries provided by minor Re/Mo solutes.The present work not only reveals a family of nanotwinned metals possessing the combination of ultra-high hardness and high thermal stability but also provides a strategy for tailoring properties of metallic materials by pairing low-angle grain boundaries and twin boundaries.