Acta Metallurgica Sinica (English Letters) ›› 2015, Vol. 28 ›› Issue (6): 671-677.DOI: 10.1007/s40195-015-0244-6

• Orginal Article • Previous Articles     Next Articles

Effect of Aging Treatment on Precipitation Behavior and Mechanical Properties of a Novel Aluminum-Lithium Alloy

Hua-Guan Li1,3, Juan Ling1, Yi-Wei Xu1, Zhong-Gang Sun2, Hong-Bing Liu2, Xing-Wei Zheng2, Jie Tao1,3()   

  1. (1)College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 211100, China
    (2)Shanghai Aircraft Manufacturing Company Limited, Shanghai, 200436, China
    (3)Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing, 211100, China
  • Received:2014-10-11 Revised:2014-12-29 Online:2015-03-05 Published:2015-07-23

Abstract:

In this work, the microstructure and precipitation phases were primarily characterized by transmission electron microscopy. The mechanical properties were evaluated by tensile and tear test. The results indicated that the samples aged at 145 °C for 45 h or 155 °C for 30 h possessed a preferable combination of strength and plasticity, owing to the precipitation of well-dispersed T1 (Al2CuLi) phases (diameter < 150 nm). However, aging at more than 165 °C caused an obvious size growth of T1 plates, leading to the quick reduction in plasticity and toughness. Furthermore, the high Cu/Li ratio resulted in distinct precipitation features, including a shorter incubation time of T1 phase and the aggravated precipitate-free zones.

Key words: Aluminum-lithium, alloy, Aging, treatment, Fracture, toughness, Microstructure