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Title: Through-thickness recrystallization characteristics of a laminated AA3xxx–AA6xxx aluminum alloy system

The through-thickness annealing behavior of a laminated AA3xxx–AA6xxx alloy system at 300 °C has been studied by scanning electron microscopy, electron backscatter diffraction analysis, electron probe micro-analysis, differential scanning calorimetry, and hardness measurement. Results show that the recrystallization process starts at the interface region between the AA3xxx (clad) and AA6xxx (core) layers. Subsequently, the recrystallization process front progresses into the core layer, while the clad layer is the last region to recrystallize. It is also found that precipitation precedes recrystallization in the entire laminate at the investigated temperature. The preferential onset of recrystallization at the interface region is attributed to the net driving pressure being the highest in this region. The factors that lead to such enhanced net driving pressure are (a) deformation incompatibility between the two alloy layers, (b) lower solute content of the interface, which also leads to lower volume fraction of precipitates, and (c) an accelerated rate of precipitate coarsening due to the presence of a higher density of dislocations. The gradual progress of recrystallization from the interface towards the core layer is dictated by precipitate coarsening and the dependence of its rate on the density of deformation-induced dislocations. The lower driving pressure due to lower workmore » hardening capacity, high solute drag pressure due to Mn, and additional Zener drag from precipitates that form due to solute redistribution during annealing explain the late initiation of recrystallization in the clad layer. - Highlights: • The through-thickness recrystallization of a laminated system is investigated. • The early onset of recrystallization at the interface is discussed. • The effects of precipitation and coarsening on recrystallization are analyzed.« less
Authors:
 [1] ; ;  [2] ;  [1]
  1. Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Ave. West, Waterloo, ON N2L 3G1 (Canada)
  2. Formerly Novelis Research and Technology Centre, 945 Princess Street, Kingston, ON K7L 5L9 (Canada)
Publication Date:
OSTI Identifier:
22476051
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Characterization; Journal Volume: 101; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALLOY SYSTEMS; ALUMINIUM ALLOYS; ANNEALING; CALORIMETRY; DEFORMATION; DIFFRACTION; DISLOCATIONS; ELECTRON MICROPROBE ANALYSIS; INTERFACES; MICROHARDNESS; PRECIPITATION; RECRYSTALLIZATION; SCANNING ELECTRON MICROSCOPY; STRAIN HARDENING