Influences of different Zr/Sc ratios on microstructure and mechanical properties of Al-2Si alloy

作者：Qinglin Li,Xiaodong Ma,Binqiang Li,Jiqiang Ma,Xiangyu Feng,Ruijie Pei,Jianjun Liu

摘要：The influences of different Zr/Sc ratios on the microstructural evolution and mechanical performances of Al-2 Si alloy were investigated in this paper.The as-cast samples were characterized and analyzed by the scanning electron microscope(SEM)with an energy dispersive spectrometer(EDS)to indicate the refining effect of the different Zr/Sc ratios on theα-Al and Si phases in Al-2 Si alloy.The results indicate that theα-Al phases are refined from coarse dendritic structure to relatively fine equiaxed grains when the Zr/Sc ratio is equal to 1:1.Meanwhile,the eutectic Si phase in Al-2 Si-0.2 Zr-0.2 Sc alloy is modified from the coarse plate and needle to fine fiber and partial granular structure,and the average roundness of eutectic Si is decreased by 75%from 16 to 4.With the refinement ofα-Al phases and the modification of eutectic Si structure,the ultimate tensile strength(UTS)is improved by 53%and the elongation(EL)is increased by 64%when the Zr/Sc ratio is equal to 1:1.In addition,the UTS decreases and EL is enhanced with the increase of tensile temperature.Moreover,the fracture model of Al-2 Si-0.2 Zr-0.2 Sc alloy in250℃changes into the ductile fracture.

发文机构：School of Materials Science and Engineering State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals School of Materials Science and Engineering

关键词：Al-SialloyZr/Scratioα-AlphasesEutecticSiMechanicalpropertiesRareearths

分类号： TG146.21[金属学及工艺—金属材料]