Calculation of Dislocation Density of Al-Zn-Mg-Cu Alloy under Severe Plastic Deformation

The variation of dislocation density has an important influence on the mechanical properties of the material and the precipitation characteristics of the strengthening phase. The dislocation density of Al-Zn-Mg-Cu alloys after severe plastic deformation was studied theoretically and experimentally by analyzing X-ray diffraction（XRD） results and combining with the corresponding theoretical model, and the dislocation density was calculated to be about 3.87×10¹⁴/m~2. The results show that the effect of dislocation density on XRD full width at half maximum（FWHM） is mainly caused by grain refinement and lattice microstrain.