A Transmission Electron Microscopy Study of the Role of Sc+Zr Addition to a 6082-T8 Alloy Subjected to Equal Channel Angular Pressing

Abstract:

The microstructural evolution with strain was investigated either in a Zr-modified 6082 Al-Mg-Si alloy and in the same alloy added with 0.117wt.% Sc, subjected to severe plastic deformations. Materials were deformed by equal-channel angular pressing using route BC, up to a true strain of ∼12. A strain of ~4 produced a sub-micrometer scale microstructure with very fine cells (nanometer scale) in the grain interior. The role of fine dispersoids (Al3(Sc1-x,Zrx)) was investigated by transmission electron microscopy techniques and discussed. Dispersoids were responsible for a more complex dislocation substructure with strain. Compared to the commercial parent alloy, block wall formation and propagation were favored by the presence of Sc-Zr containing dispersoids, while cell boundary evolution was less affected, compared to the commercial parent alloy. Mean misorientation across block walls increased with strain much more in the Sc-Zr containing alloy, reaching a plateau, starting from a true strain of ∼8. Misorientation across cell boundaries continuously increased to ∼8° and ∼5° for the Sc-Zr and Zr containing alloy, respectively.

• Periodical: Materials Science Forum (Volumes 503-504)
• Pages: 841-846
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.503-504.841
• Online since: January 2006
• Authors: Marcello Cabibbo, E. Evangelista, C. Scalabroni, Ennio Bonetti
• Keywords: Al-Mg-Si Alloy, Microstructure, Sc-Zr, Severe Plastic Deformation (SPD), TEM

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