Microstructural Characterization of an Al-Mg-Si Aluminum Alloy Processed by Equal Channel Angular Pressing

Abstract:

In the present work, a peak-aged 6061 Al-Mg-Si aluminum alloy was subjected to equal channel angular pressing (ECAP) at 110 °C. The microstructure of the sample was characterized by high-resolution transmission electron microscope and weak-beam dark-field method. It was shown that the dislocation density in some local areas is much lower than the average dislocation density expected in the usual alloys processed by severe plastic deformation. High-resolution transmission electron microscope observations indicated that many full dislocations were dissociated into partial dislocations connected by stacking faults. In addition, a Z-shaped defect (i.e., a type of dislocation locks) probably formed by the reactions of the partials in different {111} planes was first observed in the ECAPed alloy. Furthermore, the precipitation behavior and sequence in the present ECAPed sample were identified by high-resolution transmission electron microscopy.

• Periodical: Materials Science Forum (Volumes 745-746)
• Pages: 303-308
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.745-746.303
• Online since: February 2013
• Authors: Zhen Zhang, Man Ping Liu, Ying Da Yu, Pål C. Skaret, Hans Jørgen Roven
• Keywords: Al-Mg-Si Aluminum Alloy, Dislocation, Precipitation, Severe Plastic Deformation (SPD), Stacking Fault, Z-Shaped Defects

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