Oxide-dispersion-strengthened tungsten(ODS-W)and a Cu Cr Zr alloy were bonded by a three-step process:(i)surface nano-activation,(ii)copper plating followed by annealing,and(iii)diffusion bonding.The morphological and...Oxide-dispersion-strengthened tungsten(ODS-W)and a Cu Cr Zr alloy were bonded by a three-step process:(i)surface nano-activation,(ii)copper plating followed by annealing,and(iii)diffusion bonding.The morphological and structural evolutions of ODS-W and the interface of the ODS-W/CuCrZr joint during these processes have been thoroughly studied by X-ray diffraction,scanning electron microscopy,energy dispersive spectrometry,and high-resolution transmission electron microscopy.After surface nanoactivation,a nanoporous structure of ODS-W with an average pore size of~100 nm was obtained,and the Y_(2)O_(3)particles therein remained unchanged.A Cu coating was tightly bonded with the surface nanoactivated ODS-W after Cu plating and annealing.An interaction layer embedded with nanosized W particles was formed at the interface between ODS-W and plated Cu after the three-step process.Consequently,well-cohesive ODS-W/Cu and ODS-W/Y_(2)O_(3)/Cu interfaces were formed.The ODS-W/Cu Cr Zr joint showed high shear strengths(up to 201 MPa)and effective bonded area ratios(>98%).The developed three-step bonding process between ODS-W and the Cu Cr Zr alloy provides an effective support for future plasma-facing components in nuclear fusion reactor applications.展开更多
The effect of thermal treatments on mechanical properties was systematically investigated in Ni/Mo multilayers with a constant modulation period(160 nm)prepared by magnetron sputtering deposition.A supermodulus effect...The effect of thermal treatments on mechanical properties was systematically investigated in Ni/Mo multilayers with a constant modulation period(160 nm)prepared by magnetron sputtering deposition.A supermodulus effect was found in the annealed multilayers as compared to the as-deposited state.A large tensile stress development was observed in the multilayers.The evolution of grain-boundary(GB)wetting was observed at the interfaces of the multilayers,which results in an enhanced modulus based on the mechanism of GB-wetting-induced interfacial stress/strain.The GB wetting phenomenon was further supported by a thermodynamic calculation.The results not only bring clear evidence of the important role of interfacial structures in governing the elastic behavior of metallic multilayers,but also allow designing the multilayers with special properties through atomic diffusion and wetting at the interfaces based on the thermodynamic calculation.展开更多
基金supported by the National Key Research and Development Program of China(No.2017YFE0302600 and No.2018YFB0703904)。
文摘Oxide-dispersion-strengthened tungsten(ODS-W)and a Cu Cr Zr alloy were bonded by a three-step process:(i)surface nano-activation,(ii)copper plating followed by annealing,and(iii)diffusion bonding.The morphological and structural evolutions of ODS-W and the interface of the ODS-W/CuCrZr joint during these processes have been thoroughly studied by X-ray diffraction,scanning electron microscopy,energy dispersive spectrometry,and high-resolution transmission electron microscopy.After surface nanoactivation,a nanoporous structure of ODS-W with an average pore size of~100 nm was obtained,and the Y_(2)O_(3)particles therein remained unchanged.A Cu coating was tightly bonded with the surface nanoactivated ODS-W after Cu plating and annealing.An interaction layer embedded with nanosized W particles was formed at the interface between ODS-W and plated Cu after the three-step process.Consequently,well-cohesive ODS-W/Cu and ODS-W/Y_(2)O_(3)/Cu interfaces were formed.The ODS-W/Cu Cr Zr joint showed high shear strengths(up to 201 MPa)and effective bonded area ratios(>98%).The developed three-step bonding process between ODS-W and the Cu Cr Zr alloy provides an effective support for future plasma-facing components in nuclear fusion reactor applications.
基金supported by the National Key Research and Development Program of China(No.2017YFE0302600 and No.2017YFB0701801)。
文摘The effect of thermal treatments on mechanical properties was systematically investigated in Ni/Mo multilayers with a constant modulation period(160 nm)prepared by magnetron sputtering deposition.A supermodulus effect was found in the annealed multilayers as compared to the as-deposited state.A large tensile stress development was observed in the multilayers.The evolution of grain-boundary(GB)wetting was observed at the interfaces of the multilayers,which results in an enhanced modulus based on the mechanism of GB-wetting-induced interfacial stress/strain.The GB wetting phenomenon was further supported by a thermodynamic calculation.The results not only bring clear evidence of the important role of interfacial structures in governing the elastic behavior of metallic multilayers,but also allow designing the multilayers with special properties through atomic diffusion and wetting at the interfaces based on the thermodynamic calculation.
