Strength and ductility are typically mutually exclusive in traditional copper-steel joints.This work pro-poses a strategy to overcome the inherent trade-off between strength and ductility through high speed electron b...Strength and ductility are typically mutually exclusive in traditional copper-steel joints.This work pro-poses a strategy to overcome the inherent trade-off between strength and ductility through high speed electron beam welding with a preferred deflection to facilitate the in-situ formation of Fe-rich particles in the Cu matrix.The Fe-rich particles with an average diameter of 178.5 nm feature a 3D spatial network distribution across practically the entire joint.The obtained joint reinforced with such Fe-rich particles achieves ultimate high tensile strength(413 MPa)while maintaining excellent ductility(22%).The im-proved strength of the copper-steel joint is derived from the combined effects of dislocation strengthen-ing and grain refinement strengthening,while the increase in room-temperature ductility is mainly due to the high Schmid factor up to 0.454,which promotes the primary slip system to initiate easily during tensile deformation.This work provides a novel perspective on creating copper-steel joints in terms of achieving microstructural refinement and outstanding strength-ductility synergy.展开更多
基金supported by the National MCF En-ergy R&D Program(No.2022YFE03140003)the National Natural Science Foundation of China(No.12192283)the Youth Innova-tion Promotion Association CAS(No.15117008038).
文摘Strength and ductility are typically mutually exclusive in traditional copper-steel joints.This work pro-poses a strategy to overcome the inherent trade-off between strength and ductility through high speed electron beam welding with a preferred deflection to facilitate the in-situ formation of Fe-rich particles in the Cu matrix.The Fe-rich particles with an average diameter of 178.5 nm feature a 3D spatial network distribution across practically the entire joint.The obtained joint reinforced with such Fe-rich particles achieves ultimate high tensile strength(413 MPa)while maintaining excellent ductility(22%).The im-proved strength of the copper-steel joint is derived from the combined effects of dislocation strengthen-ing and grain refinement strengthening,while the increase in room-temperature ductility is mainly due to the high Schmid factor up to 0.454,which promotes the primary slip system to initiate easily during tensile deformation.This work provides a novel perspective on creating copper-steel joints in terms of achieving microstructural refinement and outstanding strength-ductility synergy.
