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Microstructure features, strengthening mechanisms and hot deformation behavior of oxide-dispersion Strengthened Al6063 alloy with ultrafine-grained structure [electronic resource]

Asgharzadeh, H ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1016/j.matchar.2012.10.007
  3. Abstract:
  4. Ultrafine-grained (UFG) Al6063/Al2O3 (0.8 vol%, 25 nm) nanocomposite was prepared via powdr metallurgy route. The grain structure of the nanocomposite composed of nano-size grains (< 0.1 μm), ultrafine grains (0.1-1 μm) and micron-size grains (>1 μm) with random orientations. It was found that the yield strength of the UFG nanocomposite is mainly controlled by the Orowan mechanism rather than the grain boundaries. The deformation activation energy at temperature ranges of T <300 ˚C and 300 ˚C ≤T < 450 ˚C was determined to be 74 and 264 kJ mol-1, respectively. At the higher temperatures, significant deformation softening was observed due to dynamic recrystallization of non-equilibrium grain boundaries. A duplex microstructure consisting of large substructured grains and fine grains separated by high-angle grain boundaries was formed after hot deformation. The deformation behavior is described based on the formation of nonequilibrium grain boundaries with high internal stress and dislocation-based models
  5. Keywords:
  6. Ultrafine-grained materials ; Aluminum matrix nanocomposite ; Microstructure ; Hot deformation ; Dynamic recrystallization
  7. Source: AIP Conference Proceedings (American Institute of Physics, Ste. 1 NO. 1 Melville NY 11747-4502 United States) ; Volume 75, January 2013, Pages 108–114
  8. URL: http://www.americanconference.com