摘要
采用光学显微镜(OM)、扫描电镜(SEM)、电子探针(EPMA)、波谱分析(WDS)、X射线衍射(XRD)以及差示扫描量热仪(DSC)等技术对Al-Zn-Mg-Cu-Zr-0.12Ce合金铸态组织及均匀化退火过程中的组织演变进行研究。结果表明:该合金铸态组织存在严重的枝晶偏析,主要由α(Al)基体、α(Al)+Mg(Zn,Al,Cu)_2非平衡共晶组织以及少量的θ(Al_2Cu)相、Al_8Cu_4Ce相、Al_7Cu_2Fe相构成;均匀化退火过程中,大量层片状共晶组织溶入基体,同时转变生成Al_2Cu Mg相;合金的过烧温度为474.87℃;合金的最佳单级均匀化退火工艺为465℃、40 h,这与均匀化动力学方程测算结果接近;合金经(435℃,8 h)+(470℃,32 h)双级均匀化退火处理后,回溶效果更好,主要残留相为难溶的Al_2CuMg相,少量含Fe杂质相以及Al_8Cu_4Ce相。
The microstructure of the as-cast Al-Zn-Mg-Cu-Zr-0.12Ce aluminum alloy and microstructure evolution during homogenization were investigated by means of optical microscopy （OM）, scanning electron microscopy （SEM）, electron probe micro-analyzer （EPMA）, wavelength dispersive spectroscopy （WDS）, X-ray diffractometry （XRD） and differential scanning calorimetry （DSC）. The results indicate that the severe dendritic segregation exists in Al-Zn-Mg-Cu-Zr-0.12Ce alloy ingot. The as-cast microstructure mainly involves a（Al）, non-equilibrium eutectics （a（Al）＋Mg（Zn, Al, Cu）2）, and small amounts ofθ（Al2Cu）, Al8Cu4Ce and Al7Cu2Fe phases. During homogenization, the lamellar eutectic structures in the as-cast alloy is dissolved into the matrix, meanwhile, a transformation from Mg（Zn, Al, Cu）2 to Al2CuMg phase also occurs. The overburnt temperature of the alloy is 474.87 ℃. The optimum parameters of single homogenization are （465 ℃, 40 h）, which is consistent with the result of homogenization kinetic analysis. The eutectic phases are eliminated more sufficiently with two-step homogenization treatment at 435 ℃ for 12 h and then at 470 ℃ for 32 h. The residual second particles after homogenization are some small Al2CuMg, Fe-rich and Al8Cu4Ce phases.
作者
袁新雄
尹登峰
余鑫祥
潘康观
卢少康
胡婷
吕正风
祝贞凤
YUAN Xin-xiong YIN Deng-feng YU Xin-xiang PAN Kang-guan LU Shao-kang HU Ting LU Zheng-feng ZHU Zhen-feng(School of Materials Science and Engineering, Central South University, Changsha 410083, China School of Engineering, Yantai Nanshan University, Yantai 265713, China)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2017年第3期459-467,共9页
The Chinese Journal of Nonferrous Metals
基金
山东省重点研发计划项目(2015GGX102021)
广东省应用型科技研发专项资金项目(2015B090926007)~~
