New Laue Micro-diffraction Setup for Real-Time In Situ Microstructural Characterization of Materials Under External Stress

Laue X-ray diffraction (XRD) is a powerful probe to characterize pressure-/strain-induced microstructural changes in materials. The use of brilliant synchrotron radiation allows Laue XRD to be measured in a fast manner, leading to microstructural characterization, such as two-dimensional maps of single-crystals, their texture, and deformation, to be made in time-resolved mode with temporal resolution down to seconds. This technique can be very efficient in the studies of mechanisms of deformation, grain growth, recrystallization, and phase transitions. A progress has been obtained to extend application of Laue diffraction to high-pressure area. Recent case studies of α → β transition in Si and α → ω transitions in Zr are briefly reported. A new experimental setup specifically optimized for real-time in situ Laue measurements has been developed at the 16-BMB beamline at the Advanced Photon Source. Due to the large X-ray energy range, which is typically up to 70 keV, a polychromatic beam diffraction technique can be efficiently implemented despite some limits introduced to the scattering angle by strain generation devices. Currently, the X-ray beam is focused at the sample position down to ~2.2 × 2.2 μm2 at the full width at the half maximum. Precision sample translation stages provide fast data collection with step sizes down to 0.5 μm.