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Effect of single and duplex aging on precipitation response, microstructure, and fatigue crack behavior in Al-Li-Cu alloy AF/C-458

  • James Fragomeni
  • Robert Wheeler
  • K. V. Jata
Testing And Evaluation

Abstract

The interrelationships between precipitate characteristics and mechanical properties of Al-Li-Cu alloy AF/C-458 were quantified. The microstructure, precipitation response, and fatigue crack growth (FCG) rates in the Al-Li-Cu alloy AF/C-458 were studied following single and duplex aging treatments for varying aging times on specimens that were given a 6% stretch after solution heat treatment. The aging response was studied using hardness and compression yield strength measurements. Quantitative transmission electron microscopy methods were used to characterize average size, volume fraction, number density, and interparticle spacing of strengthening precipitates [i.e., δ’ (Al3Li) and T1 (Al2CuLi)]. Strength and FCG rates for select heat treatments were obtained and were related to the precipitate microstructure and yield strength data.

Keywords

aging aluminum-lithium-copper fatigue hardness microstructure precipitation strengthening quantitative microscopy 

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Copyright information

© ASM International 2005

Authors and Affiliations

  • James Fragomeni
    • 1
  • Robert Wheeler
    • 2
  • K. V. Jata
    • 2
  1. 1.Department of Mechanical EngineeringThe University of Detroit Mercy, College of Engineering & ScienceDetroit
  2. 2.Air Force Research Laboratory, Materials and Manufacturing Directorate, Airforce Research Laboratory/MetalsCeramics and Nondestructive Evaluation Division/Materials and Manufacturing DirectorateWright Patterson Air Force Base

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