Evaluation of Dislocation Density in a Mg-Al-Mn-Ca Alloy Determined by X-ray Diffractometry and Transmission Electron Microscopy

Metallic materials suffering deformation store elastic strain. Evaluation of this strain energy is important for understanding the mechanical and physical properties of materials. Although direct evaluation of the stored energy is difficult, it can be evaluated by determining the defect energy of dislocations induced by the deformation. Thus, a practicable method of evaluating the strain energy is to measure the dislocation density in metallic materials. The average and representative dislocation density can be estimated by X-ray diffraction (XRD) analysis. We have estimated the dislocation density of a magnesium alloy with hexagonal crystals by a modified Warren-Averbach analysis based on a modified Williamson-Hall plot using XRD profiles. The dislocation density value obtained by this method agrees with those reported previously. We find that the modified Warren-Averbach method is still a powerful method for evaluating the dislocation density in hexagonal crystals.