Complex Precipitation Sequences of Al-Cu-Li-（Mg）Alloys Characterized in Relation to Thermal Ageing Processes
来源期刊：Acta Metallurgica Sinica2016年第1期
论文作者：Zhen Gao Jiang-Hua Chen Shi-Yun Duan Xiu-Bo Yang Cui-Lan Wu
文章页码：94 - 103
摘 要：The Al-Cu-Li-（Mg） alloy is a high-performance lightweight material strengthened by complex coexisting precipitates that form in the alloy upon thermal ageing.Using high-resolution（scanning） transmission electron microscopy in association with first-principles energy calculations,we systematically studied the complex coexisting precipitates in the alloys and correlated their precipitation sequences with thermal ageing processes applied.The principal results are the following:（1） eight types of precipitates can be observed in the alloy;（2） of these precipitates,the T1-phase is most stable.The S-phase precipitates with segregated Li atoms at their interfacial edges are unexpectedly more stable than the σ-phase;（3） the T1-phase has a characteristic precursor that plays the key role in its nucleation and growth.
Zhen Gao，Jiang-Hua Chen，Shi-Yun Duan，Xiu-Bo Yang，Cui-Lan Wu
Center for High-Resolution Electron Microscopy,College of Materials Science and Engineering,Hunan University
摘 要：The Al-Cu-Li-（Mg） alloy is a high-performance lightweight material strengthened by complex coexisting precipitates that form in the alloy upon thermal ageing.Using high-resolution（scanning） transmission electron microscopy in association with first-principles energy calculations,we systematically studied the complex coexisting precipitates in the alloys and correlated their precipitation sequences with thermal ageing processes applied.The principal results are the following:（1） eight types of precipitates can be observed in the alloy;（2） of these precipitates,the T1-phase is most stable.The S-phase precipitates with segregated Li atoms at their interfacial edges are unexpectedly more stable than the σ-phase;（3） the T1-phase has a characteristic precursor that plays the key role in its nucleation and growth.
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