caa a22 4500 463228278 CHVBK 20180405153234.0 cr unu---uuuuu 170326e20070901xx s 000 0 eng 10.1007/s10853-007-1585-y doi (NATIONALLICENCE)springer-10.1007/s10853-007-1585-y Microstructure-microhardness relationships in friction stir welded AA5251 [Elektronische Daten] [Moataz Attallah, Claire Davis, Martin Strangwood] Quantitative microstructural studies using optical and electron microscopy were carried out to determine the grain size and intermetallic particle distributions in various locations of friction stir welds in AA5251 to study their influence on the microhardness. Grain-boundary strengthening, (using Hall-Petch relation) was found to be the dominant factor controlling weld hardness within the thermomechanically-affected zone (TMAZ), yet with a minor increase in the Hall-Petch intercept from the Al-Mg alloys literature values. This deviation was associated with solid-solution strengthening resulting from the dissolution of Mg2Si particles during welding. A contribution from precipitate strengthening accounted for deviations from the overall Hall-Petch relationship. This was linked to the formation of submicron Al6(Fe,Mn) particles observed within the TMAZ grains, varying in density with position in the weld, and accordingly their strength contribution. Differential Scanning Calorimetry (DSC) was used to quantify the strengthening contribution of the dislocation stored energy in the TMAZ of the weld. Although significant stored energy was detected, this was mostly due to the presence of geometrically-necessary (non-strengthening) dislocations and did not contribute to hardness. Springer Science+Business Media, LLC, 2007 Attallah Moataz Department of Materials and Metallurgy, The University of Birmingham, Elms Road, off Pritchatts Road, B15 2TT, Edgbaston, Birmingham, UK aut Davis Claire Department of Materials and Metallurgy, The University of Birmingham, Elms Road, off Pritchatts Road, B15 2TT, Edgbaston, Birmingham, UK aut Strangwood Martin Department of Materials and Metallurgy, The University of Birmingham, Elms Road, off Pritchatts Road, B15 2TT, Edgbaston, Birmingham, UK aut Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/17(2007-09-01), 7299-7306 0022-2461 42:17<7299 2007 42 10853 https://doi.org/10.1007/s10853-007-1585-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-007-1585-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Attallah Moataz Department of Materials and Metallurgy, The University of Birmingham, Elms Road, off Pritchatts Road, B15 2TT, Edgbaston, Birmingham, UK aut NATIONALLICENCE 700 1- Davis Claire Department of Materials and Metallurgy, The University of Birmingham, Elms Road, off Pritchatts Road, B15 2TT, Edgbaston, Birmingham, UK aut NATIONALLICENCE 700 1- Strangwood Martin Department of Materials and Metallurgy, The University of Birmingham, Elms Road, off Pritchatts Road, B15 2TT, Edgbaston, Birmingham, UK aut NATIONALLICENCE 773 0- Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/17(2007-09-01), 7299-7306 0022-2461 42:17<7299 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer