高合金化Al-Zn-Mg-Cu合金铸态及均匀化态组织

As-cast and homogenized microstructure of Al-Zn-Mg-Cu alloy with high Zn content

采用热力学计算软件计算了一种高锌含量Al-Zn-Mg-Cu合金的凝固相,并采用金相显微镜、扫描电子显微镜和X射线衍射仪分析了合金的铸态、均匀化态组织。研究结果表明,合金的铸态组织主要由MgZn_2+Mg(Al,Cu,Zn)_2+α(Al)+(极少量)θ(Al_2Cu)相构成;450℃48 h均匀化退火后,Mg(Al,Cu,Zn)2仍有大量残留,470℃24 h均匀化退火后则完全回溶。

Solidification phases in a Al-Zn-Mg-Cu alloy with high Zn content were calculated by thermal dynamic calculation software. The as-cast and homogenized microstructures were analyzed by optical microscopy,scanning electronic microscopy and x-ray diffraction.The research results show that the as-cast microstructure consists of MgZn2＋ Mg（ Al,Cu,Zn）2＋ α（ Al） ＋（ trace） θ（ Al2Cu） phases. There were still a lot of residues of Mg（ Al,Cu,Zn）2 phases after homogenization at 450℃ for 48 h,while dissolved completely after homogenization at 470℃ for 24 h.