Homogenization heat treatment of 2099 Al–Li alloy
来源期刊:Rare Metals2014年第1期
论文作者:Fei Zhang Jian Shen Xiao-Dong Yan Jian-Lin Sun Xiao-Long Sun Yin Yang
文章页码:28 - 36
摘 要:The microstructure evolution and composition distribution of as-cast and homogenized 2099 aluminum– lithium(Al–Li) alloy were studied by optical microscopy(OM), differential thermal analysis(DTA), scanning electron microscopy(SEM), energy dispersive spectrometry(EDS), area and line scanning, X-ray diffraction(XRD), and Vickers microhardness test methods. The results show that severe dendrite exists in the as-cast alloy. Cu, Zn, Mn, and Mg distribute unevenly from the grain boundary to inside. The low-melting point nonequilibrium eutectic phases dissolve into the matrix during the first-step homogenization, whereas the melting point of residual eutectic phases is elevated. After the second-step homogenization, most of the remaining eutectic phases dissolve into the matrix, except a small amount of Al–Cu–Fe phases. An optimized homogenization process of the 2099 Al–Li alloy is developed(515 °C 9 18 h ? 525 °C 9 16 h), which shows a good agreement with the homogenization kinetic analysis results.
Fei Zhang1,2,Jian Shen1,Xiao-Dong Yan1,Jian-Lin Sun2,Xiao-Long Sun1,Yin Yang1
1. Nonferrous Metals Processing Division, General Research Institute for Nonferrous Metals2. School of Materials Science and Engineering, University of Science and Technology Beijing
摘 要:The microstructure evolution and composition distribution of as-cast and homogenized 2099 aluminum– lithium(Al–Li) alloy were studied by optical microscopy(OM), differential thermal analysis(DTA), scanning electron microscopy(SEM), energy dispersive spectrometry(EDS), area and line scanning, X-ray diffraction(XRD), and Vickers microhardness test methods. The results show that severe dendrite exists in the as-cast alloy. Cu, Zn, Mn, and Mg distribute unevenly from the grain boundary to inside. The low-melting point nonequilibrium eutectic phases dissolve into the matrix during the first-step homogenization, whereas the melting point of residual eutectic phases is elevated. After the second-step homogenization, most of the remaining eutectic phases dissolve into the matrix, except a small amount of Al–Cu–Fe phases. An optimized homogenization process of the 2099 Al–Li alloy is developed(515 °C 9 18 h ? 525 °C 9 16 h), which shows a good agreement with the homogenization kinetic analysis results.
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