Correlation between strength and microstructure of ball-milled Al-Mg alloys determined by X-ray diffraction

The microstructure of ball-milled Al base Al-Mg alloys is determined by the Convolutional Multiple Whole Profile fitting procedure proposed for the evaluation of X-ray diffraction peak profiles. The whole measured powder diffraction pattern is fitted by the sum of a polynomial back-round and physically well-established theoretical profile functions. The procedure provides the size distribution function of crystallites and the characteristic parameters of the dislocation structure. The mechanical strength of the specimens is correlated to the parameters of the microstructure by the Hall-Petch and the Taylor models. Both models show that the critical resolved shear stress saturates at a Mg-solute concentration of about 2 wt.% probably due to the clustering of the Mg-solute atoms. (C) 2004 Elsevier B.V. All rights reserved.