Investigation of complex residual stress states in the near-surface region: Evaluation of the complete stress tensor by X-ray diffraction pattern decomposition

The presented work introduces an alternative to the classical sin2Ψ-method for the analysis of complex stress states by X-ray diffraction, with particular focus on the near-surface region. A procedure, based on the multiple hkl-method and implemented with a generalized least square minimization routine according to the Pawley pattern decomposition, is applied for evaluating the complete residual stress tensor in molybdenum sinter-parts after severe plastic deformation. Further, the requirements on the X-ray diffraction setup and the physically meaningful description of the instrumental aberrations are discussed. Finally, the successful implementation is demonstrated.