X-RAY-DIFFRACTOMETRY OF STRESSES IN THE C ASE OF MULTIPHASE METAL-ALLOYS

Surface residual stresses take an important place in the service lifet ime of materials. X-ray diffraction is a non destructive method well a dapted to evaluate such kind of stresses. However, in multiphase mater ials, it only allows to asses to the mechanical state of one particula r constituent which is generally different from the material macroscop ic one The mechanical state of each constituent in multiphase material s, induced by an uniaxial tensile loading, has been characterized by X -ray diffraction, and predicted thanks to a micro-mechanical model. Th e experimental results have been compared with the theoretical ones to evaluate if the X-ray diffraction method can be applied to multiphase materials.