摘要
采用光学显微镜(OM)、X射线衍射(XRD)、差示扫描量热仪(DSC)和扫描电镜(SEM)及其附件能谱仪(EDX)研究Al-(7.8~9.0)Zn-1.6Mg-(1.0~2.2)Cu铝合金的铸态及其均匀化组织。结果表明:该铝合金的铸态凝固组织由α(Al)基体+Mg(Zn,Al,Cu)2非平衡共晶相组成;铸态组织中粗大非平衡共晶组织的体积分数随着Zn含量的增加而增大,且伴随其周围析出的条状、细小Mg(Zn,Al,Cu)2粒子也逐渐增多、粗化;当Cu含量(质量分数)为1.0%、1.4%、2.2%时,铸态组织晶内的独立第二相分别为T(Al2Zn3Mg3)相、S(Al2CuMg)相、T(Al2Zn3Mg3)相+θ(Al2Cu)相;各成分合金经过(470℃,24h)均匀化处理时,基体中仅剩下均匀化过程无法消除的尺寸较小、数量较少的初生富Fe相。
The microstructures of the as-cast and homogenized Al-(7.8-9.0)Zn-1.6Mg-(1.0-2.2)Cu aluminum alloys were studied by OM,XRD,DSC,SEM and EDX techniques.The results show that the as-cast microstructure of Al-(7.8-9.0)Zn-1.6Mg-(1.0-2.2)Cu aluminum alloy mainly consists of Mg(Zn,Al,Cu)2 phase and α(Al) matrix.The volume fraction of coarse eutectic-structure increases with Zn content increasing.Meanwhile,the accompanying precipitations of small Mg(Zn,Al,Cu)2 particles are also gradually increased.When Cu content(mass fraction) is 1.0%,1.4% and 2.2%,the main second phases within grains are T(Al2Zn3Mg3) phase,S(Al2CuMg) phase and T(Al2Zn3Mg3)+θ(Al2Cu) phases,respectively.The only remained particles in the matrix are some small Fe-rich particles after being homogenized at 470 ℃ for 24 h.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2010年第9期1698-1704,共7页
The Chinese Journal of Nonferrous Metals
基金
国家重点基础研究计划资助项目(2005CB623700)