【摘要】 采用金相显微镜、扫描电子显微镜和透射电子显微镜研究了微量钪对Al-Zn-Mg-Cu-Zr系合金组织的影响,测试了不同热处理状态下合金的力学性能和电导率。结果表明,添加微量Sc可以明显细化合金的铸态晶粒,显著提高Al-Zn-Mg-Cu-Zr合金的力学性能和电导率,其作用机制主要为Al3(Sc,Zr)引起的细晶强化、亚结构强化和沉淀强化;Al-9.0Zn-2.5Mg-1.2Cu-0.15Zr-0.12Sc和Al-9.5Zn-2.5Mg-1.2Cu-0.15Zr-0.12Sc经强化固溶和T6处理后,抗拉强度分别达到829.4和818.6 MPa。更多还原

【Abstract】 The microstructures of Al-Zn-Mg-Cu-Zr alloys with minor Sc were studied by using optical microscope（OM）,scanning electron microscope（SEM） and transmission electron microscope（TEM）.The tensile mechanical properties and electric conductivity of the studied alloys under different treatment conditions were tested.The results show that adding minor Sc can greatly fine the grain size of the Al-Zn-Mg-Cu-Zr alloy ingots and obviously improve the tensile properties and electric conductivity of the alloys.The strengthening mechanism is considered as fine grain strengthening,sub-structure strengthening and dispersion strengthening by Al₃（Sc,Zr）.After strengthening solution and T6,the tensile strength of Al-9.0Zn-2.5Mg-1.2Cu-0.15Zr-0.12Sc and Al-9.5Zn-2.5Mg-1.2Cu-0.15Zr-0.12Sc are 829.4,818.6 MPa respectively.更多还原