变质剂对4047铝合金组织和性能的影响

Effect of modifier on microstructure and properties of 4047 aluminum alloy

采用Sb和Eu对4047铝合金进行变质处理,研究了Sb或Eu单独变质及Sb和Eu复合变质对合金的组织、力学性能、导电率和导热性的影响。采用扫描电镜、X射线衍射仪、拉伸试验、涡流导电仪和闪光导热仪等分析了合金变质前后的组织、物相、力学性能及导电导热性能。结果表明:4047铝合金中的Si相呈长条状、多边形状及针状,合金的导电性和力学性能较差;使用0.2%~0.8%Sb单独变质时,随着Sb添加量的增加,Si相逐渐被细化为条状和颗粒状,当Sb添加量为0.6%时,合金的性能最佳;使用0.2%~0.8%Eu单独变质时,随着Eu添加量的增加,Si相逐渐变质成纤维状,当Eu添加量为0.6%时,合金的性能最佳;使用(0.6%Sb+0.6%Eu)复合变质后合金中的Si相呈丛簇小球颗粒状,比单独Sb或Eu变质的Si相更细小均匀,α-Al和Si相生长呈多向性,复合变质后合金的晶格畸变有所降低,合金的抗拉强度和伸长率分别为222.30 MPa和2.2%,导电率和热扩散系数分别为46.60%IACS和79.000 mm^(2)/s;与变质前的4047合金相比,变质后合金的抗拉强度和伸长率分别提高了85.22%和144.44%,导电率和导热性分别提高了67.93%和8.22%。

Effect of Sb or Eu modification alone and Sb and Eu composite modification on microstructure,mechanical properties,conductivity and thermal conductivity of 4047 aluminum alloy was studied.The microstructure,phase,mechanical properties,conductivity and thermal conductivity of the alloy before and after modification were analyzed by means of scanning electron microscopy,X-ray diffraction,tensile testing,eddy current conductivity meter and laser flash thermal conductivity meter.The results show that the morphology of Si phase in the 4047 aluminum alloy exhibits strip,polygonal and needle-like shapes,and the conductivity and mechanical properties of the alloy are poor.When using 0.2%-0.8%Sb is used for modification alone,as the amount of Sb added increases,the Si phase is gradually refined into strip and granular shapes.When the amount of Sb added is 0.6%,the alloy has the best performance.When 0.2%-0.8%Eu is used for modification alone,as the amount of Eu added increases,the Si phase gradually transforms into fibrous-like shape.When the amount of Eu added is 0.6%,the alloy has the best performance.After using(0.6%Sb+0.6%Eu)composite modification,the Si phase in the alloy shows in clusters and small particles shapes,which is finer and more uniform than the Si phase modified by Sb or Eu alone,the growth ofα-Al and Si phases is multi-directional,and the lattice distortion of the alloy is reduced after composite modification.The tensile strength and elongation of the alloy are 222.30 MPa and 2.2%,respectively,the conductivity and thermal diffusion coefficient are 46.60%IACS and 79.000 mm^(2)/s,respectively.Compared with the 4047 alloy before modification,the tensile strength and elongation of the modified alloy increase by 85.22%and 144.44%,respectively,while the conductivity and thermal conductivity increase by 67.93%and 8.22%,respectively.