Fourier analysis of X-ray microdiffraction profiles to characterize laser shock peened metals

Abstract

X-ray micro-diffraction profiles using a synchrotron light source were analyzed via Fourier analysis for single crystal Aluminum and Copper samples subjected to micro scale laser shock peening. Specifically, the asymmetric and broadened diffraction profiles registered across the shock peen region were analyzed by classic Warren & Averbach (W-A) method (1950) and modified W-A method (Ungar and Borbely, 1996). Average strain, mosaic size and dislocation density were extracted for the first time with spatial resolution of 5 μm. The results were compared with the simulation result obtained from FEM analysis and electron backscatter diffraction (EBSD) measurement and good agreements were seen. Difference in response caused by different materials and crystalline orientations was also studied.