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Title: Precipitation in cold-rolled Al–Sc–Zr and Al–Mn–Sc–Zr alloys prepared by powder metallurgy

The effects of cold-rolling on thermal, mechanical and electrical properties, microstructure and recrystallization behaviour of the AlScZr and AlMnScZr alloys prepared by powder metallurgy were studied. The powder was produced by atomising in argon with 1% oxygen and then consolidated by hot extrusion at 350 °C. The electrical resistometry and microhardness together with differential scanning calorimetry measurements were compared with microstructure development observed by transmission and scanning electron microscopy, X-ray diffraction and electron backscatter diffraction. Fine (sub)grain structure developed and fine coherent Al{sub 3}Sc and/or Al{sub 3}(Sc,Zr) particles precipitated during extrusion at 350 °C in the alloys studied. Additional precipitation of the Al{sub 3}Sc and/or Al{sub 3}(Sc,Zr) particles and/or their coarsening was slightly facilitated by the previous cold rolling. The presence of Sc,Zr-containing particles has a significant antirecrystallization effect that prevents recrystallization at temperatures minimally up to 420 °C. The precipitation of the Al{sub 6}Mn- and/or Al{sub 6}(Mn,Fe) particles of a size ∼ 1.0 μm at subgrain boundaries has also an essential antirecrystallization effect and totally suppresses recrystallization during 32 h long annealing at 550 °C. The texture development of the alloys seems to be affected by high solid solution strengthening by Mn. The precipitation of the Mn-containing alloy ismore » highly enhanced by a cold rolling. The apparent activation energy of the Al{sub 3}Sc particles formation and/or coarsening and that of the Al{sub 6}Mn and/or Al{sub 6}(Mn,Fe) particle precipitation in the powder and in the compacted alloys were determined. The cold deformation has no effect on the apparent activation energy values of the Al{sub 3}Sc-phase and the Al{sub 6}Mn-phase precipitation. - Highlights: • The Mn, Sc and Zr additions to Al totally suppresses recrystallization at 550 °C. • The Sc,Zr-containing particle precipitation is slightly facilitated by cold rolling. • The Mn-containing particle precipitation is highly enhanced by cold rolling. • Cold rolling has no effect on activation energy of the Al{sub 3}Sc and Al{sub 6}Mn precipitation. • The texture development is affected by high solid solution strengthening by Mn.« less
Authors:
 [1] ; ; ; ; ;  [1] ;  [2] ;  [3] ;  [4] ; ;  [5]
  1. Charles University in Prague, Faculty of Mathematics and Physics, Ke Karlovu 3, CZ-121 16 Prague (Czech Republic)
  2. King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, 23955-6900 Thuwal (Saudi Arabia)
  3. SVÚM a.s., Podnikatelská 565, CZ-190 11 Prague (Czech Republic)
  4. Czech Technical University in Prague, Faculty of Mechanical Engineering, CZ-120 00 Prague (Czech Republic)
  5. Institut für Materialprüfung und Werkstofftechnik, Freiberger Strasse 1, D-38678 Clausthal-Zellerfeld (Germany)
Publication Date:
OSTI Identifier:
22288689
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Characterization; Journal Volume: 86; Other Information: Copyright (c) 2013 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; ACTIVATION ENERGY; ALLOYS; MICROHARDNESS; MICROSTRUCTURE; PARTICLES; PHASE TRANSFORMATIONS; POWDER METALLURGY; POWDERS; PRECIPITATION; RECRYSTALLIZATION; SOLID SOLUTIONS; TEXTURE; X-RAY DIFFRACTION