Residual stress measurement in aerospace materials using neutron diffraction

Neutron diffraction is an ideal way to non-destructively characterize residual stress in engineering components. However, neutron diffraction is not an everyday tool and is best utilized in high penalty of failure parts. Aerospace parts are typically ideal specimens for neutron diffraction as they are of the scale which neutrons can provide useful maps of residual stress and the understanding of residual stress is crucial for understanding performance and lifetime of components. Neutron diffraction allows for non-destructive spatial characterization of residual stresses in engineering materials with deep penetration, as opposed to x-ray diffraction which can only characterize the surface stress state. However, neutrons are not a common laboratory tool, and require large user facilities to be operated and maintained. The residual stress diffractometer at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) High Intensity Diffractometer for Residual stress Analysis (HIDRA) features will be detailed along with recent experiments showing the new capabilities as well as experimental considerations for residual stress mapping using neutrons.