Loading...

Hot deformation of ultrafine-grained Al6063/Al2O3 nanocomposites

Asgharzadeh, H ; Sharif University of Technology | 2011

1379 Viewed
  1. Type of Document: Article
  2. DOI: 10.1007/s10853-011-5418-7
  3. Publisher: 2011
  4. Abstract:
  5. Ultrafine-grained (UFG) Al6063 alloy reinforced with 0.8 vol% nanometric alumina particles (25 nm) was prepared by reactive mechanical alloying and direct powder extrusion. Transmission electron microscopy and electron backscatter diffraction analysis showed that the grain structure of the nanocomposite composed of nanosize grains (<0.1 μm), ultrafine grains (0.1-1 μm) and micronsize grains (>1 μm) with random orientations. Mechanical properties of the material were examined at room and high temperatures by compression test. It was found that the yield strength of the UFG composite material 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. This observation indicated a change in the deformation mechanism at around 300 °C. At the higher temperatures, significant deformation softening was observed due to dynamic recrystallization of non-equilibrium grain boundaries
  6. Keywords:
  7. Compression tests ; Deformation activation energy ; Deformation mechanism ; Deformation softening ; Electron backscatter diffraction analysis ; Grain structures ; High temperature ; Higher temperatures ; Hot deformation ; Nano-size grains ; Nanometric alumina ; Non-equilibrium grain boundaries ; Orowan mechanism ; Powder extrusion ; Random orientations ; Reactive mechanical alloying ; Temperature range ; Ultra fine grain ; Ultrafine-grained ; Yield strength ; Activation energy ; Compression testing ; Dynamic recrystallization ; Grain boundaries ; Grain size and shape ; Mechanical alloying ; Mechanical properties ; Nanocomposites ; Transmission electron microscopy ; Deformation
  8. Source: Journal of Materials Science ; Volume 46, Issue 14 , July , 2011 , Pages 4994-5001 ; 00222461 (ISSN)
  9. URL: http://link.springer.com/article/10.1007%2Fs10853-011-5418-7