Evaluation of X-ray Bragg peak profiles with the variance method obtained byin situmeasurement on Mg–Al alloys

Abstract

The microstructural evolution in randomly oriented Mg–Al samples is investigatedin situduring compression by X-ray diffraction as a function of Al concentration. The diffraction data are evaluated by the variance method, which provides information about the dislocation density and spatial distribution of the dislocations. The dislocation density increases with increasing alloying content. Since the increment of the dislocation density above the yield point is linear, the mutual dislocation interaction type is determined from the Taylor equation. The results indicate the dominance of basal–basal dislocation interactions, but at higher alloying content the share of the basal–non-basal interactions increases. It is shown that the dynamics of dislocation wall formation also depend on Al content. Transmission electron microscopy observations are in agreement with the results obtained by X-ray line profile analysis.