In this study,a high entropy alloy(HEA)with remarkable mechanical performance and corrosion resistance was fabricated through L1_(2) precipitation strengthening.The tensile test at room temperature revealed that the C...In this study,a high entropy alloy(HEA)with remarkable mechanical performance and corrosion resistance was fabricated through L1_(2) precipitation strengthening.The tensile test at room temperature revealed that the CoCrFeNi_(2)Al_(0.2)Ti_(0.2)HEA,with the highest L1_(2) precipitate content,exhibited the most outstanding combination of mechanical properties characterized by a yield strength of 1656±62 MPa,a tensile strength of 1876±94 MPa,and excellent ductility of 21%±1.0%.The remarkable strength was primarily attributed to the synergistic strengthening effects of precipitation strengthening and grain boundary strengthening,whereas the excellent ductility correlates with the combined mechanisms of dislocation slip,deformation-induced stacking faults,and the Lomer-Cottrell locks.Electrochemical tests demonstrated a significant improvement in corrosion resistance with the introduction of L1_(2) precipitates.X-ray photoelectron spectroscopy analysis further revealed that the increased corrosion resistance resulted from a higher concentration of corrosion-resistant components in the passivation film,facilitated by the presence of L1_(2) precipitates.First-principles calculations revealed that the enhanced corrosion resistance is due to the higher work function and lower adsorption energy of the L1_(2) precipitates compared to the matrix phase contributes to the superior performance.This research provides valuable insights into the fabrication of high-performance alloys and offers theoretical guidance for developing next-generation materials with optimized properties.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2022YFA1603800)the National Natural Science Foundation of China(No.12274362)the open research fund of Songshan Lake Materials Laboratory(2022SLABFK01).
文摘In this study,a high entropy alloy(HEA)with remarkable mechanical performance and corrosion resistance was fabricated through L1_(2) precipitation strengthening.The tensile test at room temperature revealed that the CoCrFeNi_(2)Al_(0.2)Ti_(0.2)HEA,with the highest L1_(2) precipitate content,exhibited the most outstanding combination of mechanical properties characterized by a yield strength of 1656±62 MPa,a tensile strength of 1876±94 MPa,and excellent ductility of 21%±1.0%.The remarkable strength was primarily attributed to the synergistic strengthening effects of precipitation strengthening and grain boundary strengthening,whereas the excellent ductility correlates with the combined mechanisms of dislocation slip,deformation-induced stacking faults,and the Lomer-Cottrell locks.Electrochemical tests demonstrated a significant improvement in corrosion resistance with the introduction of L1_(2) precipitates.X-ray photoelectron spectroscopy analysis further revealed that the increased corrosion resistance resulted from a higher concentration of corrosion-resistant components in the passivation film,facilitated by the presence of L1_(2) precipitates.First-principles calculations revealed that the enhanced corrosion resistance is due to the higher work function and lower adsorption energy of the L1_(2) precipitates compared to the matrix phase contributes to the superior performance.This research provides valuable insights into the fabrication of high-performance alloys and offers theoretical guidance for developing next-generation materials with optimized properties.
