Three kinds of silver-sheathed Bi(2223) oxide superconductor tapes (single-core tape, Ag-powder-added tape and multifilamentary type) were successfully prepared, namely, through the powder-in-tube method. The critical...Three kinds of silver-sheathed Bi(2223) oxide superconductor tapes (single-core tape, Ag-powder-added tape and multifilamentary type) were successfully prepared, namely, through the powder-in-tube method. The critical current density (Jc), the Jc-B characteristics, microstructures and the relation between Jc and strain of three kinds of tapes were evaluated and compared. The maximum Jc of three kinds of tapes at 77.7 K in zero magnetic field are 28700 A/cm2 for single-core tape, 20800 A/cm2 for Ag-powder-added tape, 11700 A/cm2 for multifilamentary tape. Single-core tapes exhibit high Jc values and good Jc-B characteristics.展开更多
RE‐Ba‐Cu‐O(REBCO,where RE=Y,Gd,Sm,and other rare earth elements)coated conductor(CC)tapes are promising for applications in high‐energy physics and high‐field science owing to their significant advantages such as...RE‐Ba‐Cu‐O(REBCO,where RE=Y,Gd,Sm,and other rare earth elements)coated conductor(CC)tapes are promising for applications in high‐energy physics and high‐field science owing to their significant advantages such as high critical magnetic field,high current density,and the ability to achieve superconductivity at liquid nitrogen temperatures.Nevertheless,the mechanical and superconducting performances of these CC tapes are significantly affected by interface failures,such as interfacial delamination and coating fractures,which arise from the complex interplay of mechanical stress induced by magnet processing,thermal mismatch stress during cooling,electromagnetic stress under high magnetic fields,and thermal stress during quenching.This study comprehensively reviews the interface properties and failure behavior of REBCO CC tapes.First,the research progress in characterizing the intricate interface properties of REBCO CC is systematically reviewed.Furthermore,the interface failure behavior in extreme multifield environments was analyzed and summarized.Subsequently,this study outlines optimization strategies to mitigate interface failure risks in REBCO superconducting magnet structures.Finally,we address the current challenges and future perspectives on interface issues in REBCO CC tapes.By addressing these challenges,this study offers valuable insights for advancing the development and practical implementation of superconducting technologies in diverse applications.展开更多
The elastoplastic mechanical behaviour of an epoxy-impregnated REBCO pancake winding under cryogenics and high magnetic field is investigated in the frame of finite element(FE)modelling.A two-dimensional axisymmetric ...The elastoplastic mechanical behaviour of an epoxy-impregnated REBCO pancake winding under cryogenics and high magnetic field is investigated in the frame of finite element(FE)modelling.A two-dimensional axisymmetric electromagnetic-thermal-structure multi-physics multi-layer FE model with main layers of the coated conductor and insulation materials is developed.The radial stress and hoop stress on each constituent layer induced by thermal mismatch stress during cooling are investigated.The mechanical behaviour of each constituent material is also analysed by considering the thermal mismatch stress and electromagnetic force under 20 T background field.The results show that discrete stresses appear in all the constituent materials indicating that the multi-layer winding model containing the main constituent materials is necessary for the accurate stress analysis in an epoxy-impregnated REBCO winding.The stress of each constituent material induced by thermal mismatch during cooling process are too high to be ignored in the subsequent electromagnetic structure analysis.The mechanical-magnetic coupling analyses show that the stresses of all the constituent materials increase with the transport current.The plastic failure mainly induced by hoop stress successively occurs on copper stabilizer and Hastelloy substrate of the innermost turn,and the plastic region propagates from the inner turns to the outer turns with the increase of transport current.The failure of the superconducting layer occurs before the yield in Hastelloy due to the direct action of Lorentz force on the superconducting layers.The transverse tensile stress increases with the increasing transport current,indicating that the risk of transverse delamination failure increases with the increase of transport current.The mechanical failure modes including delamination within the conductor,plastic deformation in substrate and crack in superconducting layer should be seriously considered.展开更多
文摘Three kinds of silver-sheathed Bi(2223) oxide superconductor tapes (single-core tape, Ag-powder-added tape and multifilamentary type) were successfully prepared, namely, through the powder-in-tube method. The critical current density (Jc), the Jc-B characteristics, microstructures and the relation between Jc and strain of three kinds of tapes were evaluated and compared. The maximum Jc of three kinds of tapes at 77.7 K in zero magnetic field are 28700 A/cm2 for single-core tape, 20800 A/cm2 for Ag-powder-added tape, 11700 A/cm2 for multifilamentary tape. Single-core tapes exhibit high Jc values and good Jc-B characteristics.
基金supported by the National Natural Science Foundation of China(12272156 and 11932008)Shanghai Superconductor Technology Co.,Ltd–Lanzhou University Superconducting Materials and Mechanics Open Foundation for Industry-University-Research.
文摘RE‐Ba‐Cu‐O(REBCO,where RE=Y,Gd,Sm,and other rare earth elements)coated conductor(CC)tapes are promising for applications in high‐energy physics and high‐field science owing to their significant advantages such as high critical magnetic field,high current density,and the ability to achieve superconductivity at liquid nitrogen temperatures.Nevertheless,the mechanical and superconducting performances of these CC tapes are significantly affected by interface failures,such as interfacial delamination and coating fractures,which arise from the complex interplay of mechanical stress induced by magnet processing,thermal mismatch stress during cooling,electromagnetic stress under high magnetic fields,and thermal stress during quenching.This study comprehensively reviews the interface properties and failure behavior of REBCO CC tapes.First,the research progress in characterizing the intricate interface properties of REBCO CC is systematically reviewed.Furthermore,the interface failure behavior in extreme multifield environments was analyzed and summarized.Subsequently,this study outlines optimization strategies to mitigate interface failure risks in REBCO superconducting magnet structures.Finally,we address the current challenges and future perspectives on interface issues in REBCO CC tapes.By addressing these challenges,this study offers valuable insights for advancing the development and practical implementation of superconducting technologies in diverse applications.
基金the National Natural Science Foundation of China(11902129,11932008)the China Postdoctoral Science Foundation(2019T120963)the Fundamental Research Funds for the Central Universities(lzujbky-2020-pd03,lzujbky-2021-kb06).
文摘The elastoplastic mechanical behaviour of an epoxy-impregnated REBCO pancake winding under cryogenics and high magnetic field is investigated in the frame of finite element(FE)modelling.A two-dimensional axisymmetric electromagnetic-thermal-structure multi-physics multi-layer FE model with main layers of the coated conductor and insulation materials is developed.The radial stress and hoop stress on each constituent layer induced by thermal mismatch stress during cooling are investigated.The mechanical behaviour of each constituent material is also analysed by considering the thermal mismatch stress and electromagnetic force under 20 T background field.The results show that discrete stresses appear in all the constituent materials indicating that the multi-layer winding model containing the main constituent materials is necessary for the accurate stress analysis in an epoxy-impregnated REBCO winding.The stress of each constituent material induced by thermal mismatch during cooling process are too high to be ignored in the subsequent electromagnetic structure analysis.The mechanical-magnetic coupling analyses show that the stresses of all the constituent materials increase with the transport current.The plastic failure mainly induced by hoop stress successively occurs on copper stabilizer and Hastelloy substrate of the innermost turn,and the plastic region propagates from the inner turns to the outer turns with the increase of transport current.The failure of the superconducting layer occurs before the yield in Hastelloy due to the direct action of Lorentz force on the superconducting layers.The transverse tensile stress increases with the increasing transport current,indicating that the risk of transverse delamination failure increases with the increase of transport current.The mechanical failure modes including delamination within the conductor,plastic deformation in substrate and crack in superconducting layer should be seriously considered.