Sc、Zr对Al-Zn-Mg-Cu合金组织与性能的影响

制备了成分Al-5．8Zn-2．5Mg-1．6Cu-0．2Cr和Al-5．8Zn．2．5Mg-1．6Cu-0．2Cr-0．23Sc-0．12Zr的两种合金。通过金相显微镜及电镜观察、力学性能及腐蚀性能测试，分析了两种合金不同处理状态的显微组织及其不同状态下的力学性能和腐蚀性能。结果表明，添加Sc、Zr能显著细化合金的铸态组织，对合金的力学性能及腐蚀性能也起到极大的提高作用。添加Sc、Zr的2#合金与1#合金相比较，经T6处理后，前者的抗拉强度提高110N／mm^2，屈服强度提高91N／mm^2，伸长率也略有提高。

Effects of Sc and Zr addition on microstructures and properties of Al-Zn-Mg-Cu alloys

Two kinds of Al-Zn-Mg-Cu alloys with and without Sc and Zr were produced.The microstructure of the two alloys under different treatment conditions were studied by using optical microscope and transmission electron microscope(TEM).The mechanical properties and corrosion capability were investigated by cold tensile test,scanning electron microscope(SEM) and corrosion experiment.The results show that adding trace Sc and Zr can greatly fine the grain size of the Al-Zn-Mg-Cu alloy ingots and obviously improve the tensile properties and corrosion resistance of the Al-Zn-Mg-Cu-Zr alloys.The alloy which adds with Sc and Zr has 110(N/mm~2) higher in tensile strength and 91 N/mm~2 higher in bend strength than the alloy without after T6 process,and its ductility also improves a little.