【摘要】 采用拉伸力学性能、硬度、电导率测试以及X线衍射(XRD)物相分析和电子显微分析技术研究Al-Zn-Mg-Sc-Zr合金板材在制备过程中的组织性能演变。研究结果表明:铸态合金在350℃/8 h单级均匀化处理过程中析出细小弥散的Al3(Sc,Zr)粒子,但同时也析出大量粗大T相,合金过饱和度降低,强度下降;在350℃/8h+470℃/24 h双级均匀化第二级过程中,T相回溶入基体,而Al3(Sc,Zr)粒子特性基本上没有发生变化;由于Al3(Sc,Zr)粒子的抑制再结晶作用,合金热轧、退火以及冷轧后固溶状态下为纤维状变形组织;时效后合金析出大量细小弥散分布的η′相,具有很强的强化效果。更多还原

【Abstract】 The Microstructure and properties evolution of Al-Zn-Mg-Sc-Zr alloy sheet in different treat conditions during preparation process were studied by hardness,tensile tests,electric conductivity measurement,X-ray diffraction(XRD) and electronic microscopy analysis.The results show that though fine dispersed Al3(Sc,Zr) particles precipitated in single homogenization treated at 350 ℃ for 8 h,the strength of the alloy decreases on account of the decline of supersaturation because of the precipitation of T phase.During two-step homogenization,treated at 350 ℃ for 1 h followed by 470 ℃ for 24 h treatment,T phase dissolves into the matrix again,while Al3(Sc,Zr) particles remain almost the same as the size in the second step.Deformation microstructure is observed in rolling,annealing and solution state due to the resistance effect to recrystallization by Al3(Sc,Zr) particles.During the aging process,the strength increases significantly owing to the fine dispersed η′ phases precipitated from the solid solution.更多还原