固溶处理对Al-9.0Zn-2.8Mg-2.5Cu-0.12Zr-0.03Sc铝合金组织性能的影响.pdfVIP

Trans. Nonferrous Met. Soc. China 23(2013) 2537−2542 Effects of solution treatment on microstructure and mechanical properties of Al−9.0Zn−2.8Mg−2.5Cu−0.12Zr−0.03Sc alloy Gao-song WANG, Zhi-hao ZHAO, Yi-hang ZHANG, Jian-zhong CUI Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110819, China Received 23 July 2012; accepted 11 March 2013 Abstract: Effects of additions minor contents of 0.03% Sc and 0.12% Zr and solution treatment on microstructure and mechanical properties of Al−9.0Zn−2.8Mg−2.5Cu alloy were studied by metallographic microscopy, differential thermal analysis (DSC) and transmission electron microscopy (TEM), in order to obtain high-performance Al alloys. The minor additions of Sc (less than 0.1%) were carried out. The results show that with the additions of 0.03% Sc and 0.12% Zr, the petaloid Al3(Sc,Zr) precipitated phases occur in Al−9.0Zn−2.8Mg−2.5Cu alloy, and Al (Sc,Zr) particles obviously hinder the recrystallization of Al−9.0Zn−2.8Mg−2.5Cu 3 alloy during homogenizing and extruding processes due to their strong pinning effect on dislocation. Multi-stage solution is better than single solution, for it can avoid recrystallization of Al−9.0Zn−2.8Mg−2.5Cu alloy with the minor contents of Sc (less than 0.1%). The proper solution treatment is (420 °C, 3 h)+(465 °C, 2 h) under which Al−9.0Zn−2.8Mg−2.5Cu−0.12Zr−0.03Sc alloy obtains a tensile strength of 777.29 MPa and a elongation of 11.84%. Key words: Al−Zn−Mg−Cu Alloy; solution treatment; structure; mechanical properties alloys with can be