Al-Cu-Li合金均匀化处理参数优化和微观组织演化（英文）
发布时间：2018-09-19 18:59
【摘要】：对Al-Cu-Li铸态合金进行单级和双级均匀化处理,通过光学显微镜(OM)、扫描电镜(SEM)、能谱分析(EDS)、X衍射(XRD)和差热分析(DSC)研究合金元素分布和微观组织演化。结果表明:Al-Cu-Li合金铸态组织存在严重枝晶偏析,由晶内到晶界Cu元素分布十分不均匀,Mg、Zn、Mn和Ag变化不明显。晶界处存在大量的非平衡共晶相,主要包括Al_2Cu、含有少量Mg元素的Al_2Cu相,以及Al_2Cu Mg相。经双级均匀化(495℃/24 h+515℃/_24 h)处理后,大部分非平衡共晶相和部分第二相(Al_2Cu Mg和Al_2Cu Li)溶解到合金基体,但仍有部分富-Fe和富-Mn相残留在晶界不能回溶。Al_2Cu Mg相的熔点低于Al_2Cu相,两者分别在495和515℃先后溶解。通过均匀化动力学分析,确定Al-Cu-Li铝锂合金最佳的均匀化制度为495℃/24 h+515℃/24 h,该双级均匀化制度与动力学分析结果一致。
[Abstract]:Single stage and two stage homogenization treatment was carried out on the as-cast Al-Cu-Li alloy. The element distribution and microstructure evolution of the as-cast Al-Cu-Li alloy were studied by means of (OM), scanning electron microscope (SEM),) and differential thermal analysis (DSC), which were characterized by (EDS) X diffraction (XRD) and differential thermal analysis (DTA). The results show that there is a serious dendritic segregation in the as-cast microstructure of the alloy, and the distribution of Cu elements from the inner grain to the grain boundary is very uneven. There are no obvious changes in mn and Ag in the as-cast structure of the alloy. There are a large number of non-equilibrium eutectic phases at grain boundaries, including the Al_2Cu phase with a small amount of Mg elements in Al_2Cu, and the Al_2Cu Mg phase. After two-stage homogenization (495 鈩，
本文编号：2251030
[Abstract]:Single stage and two stage homogenization treatment was carried out on the as-cast Al-Cu-Li alloy. The element distribution and microstructure evolution of the as-cast Al-Cu-Li alloy were studied by means of (OM), scanning electron microscope (SEM),) and differential thermal analysis (DSC), which were characterized by (EDS) X diffraction (XRD) and differential thermal analysis (DTA). The results show that there is a serious dendritic segregation in the as-cast microstructure of the alloy, and the distribution of Cu elements from the inner grain to the grain boundary is very uneven. There are no obvious changes in mn and Ag in the as-cast structure of the alloy. There are a large number of non-equilibrium eutectic phases at grain boundaries, including the Al_2Cu phase with a small amount of Mg elements in Al_2Cu, and the Al_2Cu Mg phase. After two-stage homogenization (495 鈩，
本文编号：2251030
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