Acoustic emission (AE) was measured in Al 4.5% Mg alloys with varying amounts of additional elements which form precipitates in this system. During tensile testing, the samples deformed inhomogeneously with multiple yield points - often called Lueders bands. calculated strain rates during Lueders bands. Calculated strain rates during Lueders deformation were greater than 10 s(minus) (sup 1). Three distinct regions could be observed in close examination of the drop in stress associated with the yield points. The AE signal peak was found to occur during the region of steepest decrease in the stress. The magnitude of the stress drops which is proportional to the amount of plastic deformation in the individual yield points correlated well with the height of the corresponding rms voltage bursts.
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