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Microstructural features, texture and strengthening mechanisms of nanostructured Al6063 alloy processed by powder metallurgy [electronic resource]

Asgharzadeh, H ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1016/j.msea.2011.01.082
  3. Abstract:
  4. Nanostructured AA6063 (NS-Al) powder with an average grain size of ∼100 nm was synthesized by high-energy attrition milling of gas-atomized AA6063 powder followed by hot extrusion. The microstructural features of the consolidated specimen were studied by transmission electron microscopy (TEM) and electron backscatter diffraction (EBSD) techniques and compared with those of coarse-grained AA6063 (CG-Al) produced by hot powder extrusion of gas-atomized powder (without using mechanical milling). The consolidated NS-Al alloy consisted of elongated ultrafine grains (aspect ratio of ∼2.9) and equiaxed nanostructured grains. A high fraction (∼78%) of high-angle grain boundaries with average misorientation angle of 33° was noticed. Microtexture evaluation by plotting pole-figures and orientation distribution function (ODF) analysis showed Copper and P texture components for both the consolidated Al alloys. Tensile test at room temperature and microhardness measurement revealed that a significant improvement in the strength of AA6063 alloy is obtained through refinement of the grain structure. The strengthening mechanisms are discussed based on the dislocation-based models. The role of high-angle and low-angle grain boundaries on the strengthening mechanisms is discussed
  5. Keywords:
  6. Nanostructured materials ; Aluminum alloys ; Microstructure ; Texture ; Strengthening mechanism
  7. Source: Journal of Materials Science and Engineering: A ; 15 May 2011, Volume 528, Issue 12, Pages 3981–3989
  8. URL: http://www.sciencedirect.com/science/article/pii/S0921509311001043