화학공학소재연구정보센터
Materials Science Forum, Vol.443-4, 91-94, 2004
Reconstruction of stress and composition profiles from X-ray diffraction experiments - How to avoid ghost stresses?
On evaluating lattice strain-depth or stress-depth profiles with X-ray diffraction, the variation of the information depth while combining various tilt angles, psi, in combination with lattice spacing gradients leads to artefacts, so-called ghost or fictitious stresses. X-ray diffraction lattice-strain analysis was simulated for a model stress-depth profile combined with a composition-depth profile. Two principally different methods were investigated for the reconstruction of the actual stress and composition profiles from the simulated data: considering the stress/strain determined at a specific depth as a weighted average over the actual stress/strain depth profile considering the lattice spacing determined at a specific depth, for a specific value for psi, as a weighted average over the actual lattice spacing profile for this psi-direction. On the basis of the results it is possible to propose a preferred method for the evaluation of stress/strain and composition profiles, while minimising the risk for ghost stresses.