As a novel method to reduce the temperature during electron beam welding,and to subsequently inhibit interfacial reaction between SiC and Al matrix,the electron beam surface heating-diffusion bonding is proposed for j...As a novel method to reduce the temperature during electron beam welding,and to subsequently inhibit interfacial reaction between SiC and Al matrix,the electron beam surface heating-diffusion bonding is proposed for joining SiC particle reinforced aluminum alloy metal-matrix composite of 45 vol.%SiC/2024 Al.The defocused electron beam was used to heat the base metal surface,and the simultaneous pressure was applied to the butt surface to achieve bonding.The base metals were successfully joined by diffusion.The maximum temperature of the whole joint was effectively decreased to less than 650°C.The Gibbs free energy change of interfacial reaction was calculated,meaning a positive value reaching 218 kJ/mol and a consequently prominent inhibitory effect on the formation of brittle Al_(4)C_(3)that was proved by microstructural observation.The tensile strength for the bonded joint was increased by 35%compared to that for ordinary welded joint.When the TC4 layer was added,TiC strengthening particles were formed with the deficiency of Al_(4)C_(3),corresponding to the significantly increased tensile strength of 63%of base metal(154 MPa).展开更多
基金supported by the National Natural Science Foundation of China(grant no.51774106)。
文摘As a novel method to reduce the temperature during electron beam welding,and to subsequently inhibit interfacial reaction between SiC and Al matrix,the electron beam surface heating-diffusion bonding is proposed for joining SiC particle reinforced aluminum alloy metal-matrix composite of 45 vol.%SiC/2024 Al.The defocused electron beam was used to heat the base metal surface,and the simultaneous pressure was applied to the butt surface to achieve bonding.The base metals were successfully joined by diffusion.The maximum temperature of the whole joint was effectively decreased to less than 650°C.The Gibbs free energy change of interfacial reaction was calculated,meaning a positive value reaching 218 kJ/mol and a consequently prominent inhibitory effect on the formation of brittle Al_(4)C_(3)that was proved by microstructural observation.The tensile strength for the bonded joint was increased by 35%compared to that for ordinary welded joint.When the TC4 layer was added,TiC strengthening particles were formed with the deficiency of Al_(4)C_(3),corresponding to the significantly increased tensile strength of 63%of base metal(154 MPa).
