成品退火工艺对Cu-20wt%Fe原位复合带材组织和性能的影响

通过拉伸性能和导电率测试、扫描电镜微观组织观察和能谱分析,研究了不同成品退火工艺下Cu-20wt%Fe原位复合带材的抗拉强度、导电率和富铁相的变化规律。结果表明,经退火处理后,部分厚度较小的富铁相可以回溶到铜基体中,随着退火温度的升高,富铁相回溶增多,残留的扁长富铁相最终呈断续分布。带材抗拉强度随退火时间的延长先显著下降至380~440 MPa,随后下降速率明显放缓,甚至出现轻微波动上升,最终趋于平稳,而退火温度越高,抗拉强度越低。带材导电率随退火时间的延长迅速提高至31%IACS~37%IACS,随后变化缓慢、略有波动,最终趋于平稳。Cu-20wt%Fe原位复合带材较理想退火工艺为450 ℃×60 min。

Effect of finished product annealing process on microstructure and properties of Cu-20wt%Fe in-situ composite strip

Varying rules of tensile strength, electrical conductivity and iron-rich phase evolution of Cu-20wt%Fe in-situ composite strips under different finished product annealing processes were studied by means of tensile test, electrical conductivity test, SEM microstructure observation and energy spectrum analysis. The results show that after annealing, some iron-rich phases with small thickness can be dissolved into copper matrix. With the increase of annealing temperature, the dissolution of iron-rich phase increases, and the residual flat and long iron-rich phases eventually distribute intermittently. With the extension of annealing time, the tensile strength of the strip first decreases significantly to 380-440 MPa, then the decline rate slows down significantly, even fluctuates up slightly, and finally tends to be stable, meanwhile, the tensile strength decreases with the increase of annealing temperature. The conductivity of the strip increases rapidly to 31%IACS-37%IACS with the extension of annealing time, then changes slowly, fluctuates slightly, and finally tends to be stable. The ideal finished product annealing process for Cu-20wt%Fe in-situ composite strip is at 450 ℃ for 60 min.