As an advanced solid state bonding process,plastic deformation bonding(PDB)is a highly reliable metallurgical joining method that produces significant plastic deformation at the bonding interface of welded joints thro...As an advanced solid state bonding process,plastic deformation bonding(PDB)is a highly reliable metallurgical joining method that produces significant plastic deformation at the bonding interface of welded joints through thermo-mechanical coupling.In this study,PDB behavior of IN718 superalloy was systematically investigated by performing a series of isothermal compression tests at various processing conditions.It was revealed that new grains evolved in the bonding area through discontinuous dynamic recrystallization(DDRX)at 1000–1150℃.Electron backscattered diffraction(EBSD)and transmission electron microscopy(TEM)results revealed that the bonding of joints is related with interfacial grain boundary(IGB)bulging process,which is considered as a nucleation process of DRXed grain under different deformation environments.During recrystallization process,the bonded interface moved due to strain-induced boundary migration(SIBM)process.Stored energy difference(caused by accumulation of dislocations at the bonding interface)was the dominant factor for SIBM during DRX.The mechanical properties of the bonded joints were dependent upon the recrystallized microstructure and SIBM ensued during PDB.展开更多
Plastic deformation bonding(PDB)has emerged as a promising solid state bonding technique with limited risk of phase transformations and residual thermal stresses in the joint.In this study,the PDB behavior of IN718 su...Plastic deformation bonding(PDB)has emerged as a promising solid state bonding technique with limited risk of phase transformations and residual thermal stresses in the joint.In this study,the PDB behavior of IN718 superalloy was systematically investigated by performing a series of isothermal compression tests at various processing conditions.It was revealed that,with increasing PDB strain rate at 1000?C,different extents of dynamic recrystallization(DRX)occur in the bonding area of IN718 joints.The extent of DRX,average size of DRXed grains,and a newly proposed"interfacial bonding ratio(?Bonding)"parameter(to quantify the bond quality)were initially reduced with increase in the strain rate up to 0.1 s-1 and later increased at further higher strain rates.Electron backscattered diffraction(EBSD)and transmission electron microscopy(TEM)based interfacial microstructure analyses indicated that the quality of the bonded joints is closely related with the development of fine DRXed grains at the bonding interface with the increasing strain,which promotes adiabatic temperature rise.It was revealed that the initial bulging and subsequent migration of the original interfacial grain boundary(IGB)were the main mechanisms promoting DRX in the well bonded IN718 superalloy joints.Moreover,the mechanical properties of the bonded joints were not only controlled by the recrystallized microstructure but also depended upon the Bonding parameter of the joints.展开更多
基金the National Key Research and Development Program[grant number 2018YFA0702900]the National Natural Science Foundation of China[grant numbers U1508215,51774265]+2 种基金the National Science and Technology Major Project of China[Grant No.2019ZX06004010]the Key Program of the Chinese Academy of Sciences[Grant No.ZDRW-CN-2017-1]the CAS Interdisciplinary Innovation Team。
文摘As an advanced solid state bonding process,plastic deformation bonding(PDB)is a highly reliable metallurgical joining method that produces significant plastic deformation at the bonding interface of welded joints through thermo-mechanical coupling.In this study,PDB behavior of IN718 superalloy was systematically investigated by performing a series of isothermal compression tests at various processing conditions.It was revealed that new grains evolved in the bonding area through discontinuous dynamic recrystallization(DDRX)at 1000–1150℃.Electron backscattered diffraction(EBSD)and transmission electron microscopy(TEM)results revealed that the bonding of joints is related with interfacial grain boundary(IGB)bulging process,which is considered as a nucleation process of DRXed grain under different deformation environments.During recrystallization process,the bonded interface moved due to strain-induced boundary migration(SIBM)process.Stored energy difference(caused by accumulation of dislocations at the bonding interface)was the dominant factor for SIBM during DRX.The mechanical properties of the bonded joints were dependent upon the recrystallized microstructure and SIBM ensued during PDB.
基金supported by the National Key Research and Development Program[grant number 2018YFA0702900]the National Natural Science Foundation of China[grant numbers U1508215,51774265]+2 种基金the National Science and Technology Major Project of China[Grant No.2019ZX06004010]the Key Program of the Chinese Academy of Sciences[grant number ZDRW-CN-20171]Program of CAS Interdisciplinary Innovation Team.
文摘Plastic deformation bonding(PDB)has emerged as a promising solid state bonding technique with limited risk of phase transformations and residual thermal stresses in the joint.In this study,the PDB behavior of IN718 superalloy was systematically investigated by performing a series of isothermal compression tests at various processing conditions.It was revealed that,with increasing PDB strain rate at 1000?C,different extents of dynamic recrystallization(DRX)occur in the bonding area of IN718 joints.The extent of DRX,average size of DRXed grains,and a newly proposed"interfacial bonding ratio(?Bonding)"parameter(to quantify the bond quality)were initially reduced with increase in the strain rate up to 0.1 s-1 and later increased at further higher strain rates.Electron backscattered diffraction(EBSD)and transmission electron microscopy(TEM)based interfacial microstructure analyses indicated that the quality of the bonded joints is closely related with the development of fine DRXed grains at the bonding interface with the increasing strain,which promotes adiabatic temperature rise.It was revealed that the initial bulging and subsequent migration of the original interfacial grain boundary(IGB)were the main mechanisms promoting DRX in the well bonded IN718 superalloy joints.Moreover,the mechanical properties of the bonded joints were not only controlled by the recrystallized microstructure but also depended upon the Bonding parameter of the joints.
