Effects of surface roughness on interfacial dynamic recrystallization and mechanical properties of Ti-6Al-3Nb-2Zr-1Mo alloy joints produced by hot-compression bonding  

作　　者：Bijun Xie Zhenxiang Yu Haiyang Jiang Bin Xu Chunyang Wang Jianyang Zhang Mingyue Sun Dianzhong Li Yiyi Li 

机构地区：[1]Key Laboratory of Nuclear Materials and Safety Assessment,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [2]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [3]College of Materials Science and Engineering,University of Science and Technology of China,Hefei 230026,China

出　　处：《Journal of Materials Science & Technology》2022年第1期199-211,共13页材料科学技术（英文版）

基　　金：financially supported by the National Key Research and Development Program(No.2018YFA0702900);the Postdoctoral Science Foundation of China(No.2020M681004);the National Natural Science Foundation of China(No.51774265);the National Science and Technology Major Project of China(No.2019ZX06004010);the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDC04000000)。

摘　　要：The influence of surface roughness on the interfacial dynamic recrystallization kinetics and mechanical properties of Ti-6 Al-3 Nb-2 Zr-1 Mo hot-compression bonding joints was systematically investigated.It is found that for the bonding interface of rough surfaces,elongated fine grains are formed at the bonding interface due to shear deformation of the interfacial area.As the surface roughness increases,the proportion of elongated grains drastically decreases as they further reorient to form equiaxed grains along the bonding interface of rougher surfaces resulting from severe incompatible deformation of the interface area.Meanwhile,high-density geometrically necessary dislocations accumulate around the interfacial recrystallization area to accommodate the incompatible strain and lattice rotation.A rotational dynamic recrystallization mechanism is thereby proposed to rationalize the formation of fine interfacial recrystallization grains during bonding of rough surfaces.In contrast to that of rough surfaces,bonding interface of polished surfaces exists in the form of straight interface grain boundaries without fine grains under the same deformation conditions.While with the increase of deformation strain,small grain nuclei form along the bonding interface,which is associated with discontinuous dynamic recrystallization assisted by strain-induced boundary migration of interface grain boundaries.Moreover,the bonding joints of rough surfaces show lower elongation compared with that of polished surfaces.This is because the formation of heterogeneous fine grains with low Schmid factor along the bonding interface of rough surfaces,leading to worse compatible deformation capability and thereby poor ductility of bonding joints.

关 键 词：Surface roughness Rotational dynamic recrystallization EBSD Geometrically necessary dislocations Mechanical properties 

分 类 号：TG146.23[一般工业技术—材料科学与工程]