Acta Metallurgica Sinica (English Letters) ›› 2010, Vol. 23 ›› Issue (4): 285-292.DOI: 10.11890/1006-7191-104-285

• 研究论文 • 上一篇    下一篇

Effect of Indium on the precipitation process in Al-3.3Cu-0.7Li alloy

潘峥嵘1,郑子樵2,廖忠全2,李世晨2   

  1. 1. 中南大学
    2. Central South University
  • 收稿日期:2010-01-11 修回日期:2010-04-20 出版日期:2010-08-25 发布日期:2010-08-11
  • 通讯作者: 潘峥嵘

Effect of Indium on the precipitation process in Al-3.3Cu-0.7Li alloy

Zhengrong PAN, Ziqiao ZHENG, Zhongquan LIAO, Shichen LI   

  1. School of Materials Science and Engineering, Central South University, Changsha 410083, China
  • Received:2010-01-11 Revised:2010-04-20 Online:2010-08-25 Published:2010-08-11
  • Contact: Zhengrong PAN

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摘要：

The effects of 0.5wt% Indium on Al-3.3Cu-0.8Li alloy were studied. Instead of T1 (Al2CuLi) phase, there was an unknown cubic phase acting as the dominant precipitates in the In-added alloy in T6 temper, which disappeared in T8 temper. The orientation relationship between this phase and matrix was given by SAEDs: (001)p//(001)α, [010]p//[010]α. Both measuring directly from HREM images or calculating from it’s FFTs gave an close lattice parameter about 0.83nm. 3DAP composition analysis revealed the presence of Al, Cu and Li in the atomic percentages: 60%Al, 30%Cu and 10% Li. Thus, this cubic phase is considered to be Li-rich γ1 (Al4Cu9) phase or a new phase designated as χ (Al5Cu6Li2). Different from the traditional reported providing heterogeneous nucleation sites for the precipitates, Indium was detected neither around nor in the cubic phase by EDX and 3DAP.

关键词: Inium, Precipitation, Microstructure, HRTEM, 3DAP

Abstract:

The effects of 0.5 wt pct In on Al-3.3Cu-0.8Li alloy were studied. Instead of T1 (Al2CuLi) phase, there was an unknown cubic phase acting as the dominant precipitates in the In-added alloy in T6 temper, which disappeared in T8 temper. The orientation relationship between this phase and matrix was given by SAEDs: (001)p//(001)α, [010]p//[010]α. Both measuring directly from HREM images or calculating from it's FFTs gave an close lattice parameter about 0.83~nm. 3DAP composition analysis revealed the presence of Al, Cu and Li in the atomic percentages: 60%Al, 30%Cu and 10%Li. Thus, this cubic phase is considered to be Li-rich γ1 (Al4Cu9) phase or a new phase designated as χ (Al5Cu6Li2). Different from the traditional report providing heterogeneous nucleation sites for the precipitates, In was detected neither around nor in the cubic phase by EDX and 3DAP.

Key words: Indium, Precipitation, Microstructure, HRTEM, 3DAP