Regensburg 2004 – scientific programme
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M: Metallphysik
M 30: Mechanische Eigenschaften V
M 30.3: Talk
Thursday, March 11, 2004, 15:15–15:30, H4
On the influence of obstacles (precipitates/particles) on the PLC effect in Al-Mg alloys — •Hanno Dierke, Fabian Krawehl, and Hartmut Neuhäuser — TU Braunschweig, Institut für Metallphysik und Nukleare Festkörperphysik, Mendelssohnstr. 3, 38106 Braunschweig
Due to their low weight and high mechanical strength AlMg alloys provide a large variety of applications as material for lightweight construction. However, the practical benefit is limited due to instabilities and inhomogeneities caused by correlated movement of dislocations during plastic deformation (PLC effect). By addition of unshearable obstacles the formation of dislocation avalanches may be prevented or at least reduced.
The alloy AA5754 was investigated particularly with regard to the influence of obstacles on the movement of dislocations. For this purpose on the one hand in the samples precipitates were produced by heat treatments, on the other hand metal matrix composites (MMCs) with different volume fractions of Al2O3 particles were investigated. The experiments were performed in strain controlled experiments at room temperature and at strain rates between 1·10−6 and 5·10−3s−1. In addition some samples were investigated by TEM to find correlations between deformation behaviour and microstructure.