Zhiwei DU
,
Tietao ZHOU
,
Peiying LIU
,
Huanxi LI
,
Baozhong DONG
,
Changqi CHEN
材料科学技术（英）
The evolution of microstructure parameters (precipitate size and volume fraction) for two types of Al-Zn-Mg-Cu alloys (7075 and 7055) during aging has been studied by synchrotron-radiation small angle X-ray scattering (SAXS). The results show that the precipitates are only a few nanometers for both alloys ageing even at higher temperature of 160℃ for 72 h (4.44 and 5.82 nm, respectively). The maximum of the precipitate volume fraction increases with in creasing Zn content and is about 0.023~0.028 and 0.052~0.054, respectively. The coarsening of precipitate is consistent with LSW (Lifshitz-Slyozov-Wagner) model even at the initial stage where volume fraction is still varying. The activation energy of coarsening regime has been determined to be about 1.22±0.02 eV and 1.25±0.02 eV for alloys 7075 and 7055, respectively.
关键词:
Small angle X-ray scattering (SAXS)
,
null
,
null
,
null
,
null
戴晓元
,
李妮
,
熊亮
材料导报
doi:10.11896/j.issn.1005-023X.2015.03.014
Al-Zn-Mg-Cu合金密度小,比强度高,具有良好的加工性能,是现代航空航天武器装备等领域发展的关键结构材料.但是对于大型结构件,该系铝合金表现出一定的淬火敏感性.综述了Al-Zn-Mg-Cu合金淬透性研究方法和影响该系铝合金淬透性的因素.其中淬透性研究方法包括:端淬-硬度试验法测定铝合金淬透层深度、TTP曲线、CCT曲线、TTT曲线、理论计算法以及计算机数值模拟法.并且从合金的化学成分、轧制制度、均匀化制度、淬火制度、时效制度和几何尺寸等方面分析了影响淬透性的因素.
关键词:
7000系铝合金
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淬透性
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淬透层深度
