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Hot deformation of PM Al6061 alloy produced by sintering and powder extrusion

Asgharzadeh, H ; Sharif University of Technology | 2008

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  1. Type of Document: Article
  2. DOI: 10.1179/174329008X286695
  3. Publisher: 2008
  4. Abstract:
  5. Compression test was used to study the deformation behaviour of sintered (12% porosity) and powder extruded (1% porosity) Al6061 alloy at high temperatures ranging from 350 to 500°C. The flow curves of the materials were determined at strain rates of 0.001, 0.01 and 0.1 s-1. The extruded alloy exhibited plastic instability in the form of bulging and formation of shear bands. The deformation activation energy of the extruded material was determined to be QI=77±16 kJ mol-1 (T<450°C) and OII=136±12 kJ mol-1 (T≥450°C). The values of activation energy and appearance of strain softening in the stress-strain curves revealed that thermally activated restoration processes, i.e. dynamic recovery and dynamic recrystallisation, occurred. The sintered compact exhibited geometrical strain hardening during deformation with a limited ductility at temperatures <450°C. Pores and cracks were formed in the bulged region due to localised tensile stresses. © 2008 Institute of Materials, Minerals and Mining
  6. Keywords:
  7. Al6061 alloy ; Compression tests ; Deformation activation energies ; Deformation behaviours ; Dynamic recoveries ; Dynamic recrystallisation ; Extruded alloys ; Extruded materials ; Flow curves ; High temperatures ; Hot deformation ; Plastic instabilities ; Powder extrusions ; Restoration process ; Sintered compacts ; Strain softening ; Thermally activated ; Alloys ; Compression testing ; Deformation ; Microstructure ; Porosity ; Powders ; Recrystallization (metallurgy) ; Sintering ; Strain hardening ; Strain rate ; Stress-strain curves ; Tensile strength ; Activation energy
  8. Source: Powder Metallurgy ; Volume 51, Issue 4 , July , 2008 , Pages 354-360 ; 00325899 (ISSN)
  9. URL: https://www.tandfonline.com/doi/abs/10.1179/174329008X286695