Combining Laue Microdiffraction and Digital Image Correlation for Improved Measurements of the Elastic Strain Field with Micrometer Spatial Resolution

The X-ray Laue microdiffraction technique, available at beamline BM32 on the synchrotron ESRF, is ideally suited for probing the field of elastic strain (and associated stress) in deformed polycrystalline materials with a micrometric spatial resolution. We show that using Digital Image Correlation for measuring Laue pattern distortions between two mechanical states improves significantly the estimate of elastic strain increment. The potentiality of this new Laue-DIC method is illustrated on an elastically bent Si single crystal, for which the measured elastic strain deviates not more than 10-5 from the theoretical strain distribution provided by standard solutions.