(National Engineering Research Center of Light Alloy Net Forming，School of Materials Science and Engineering， Shanghai Jiao Tong University，Shanghai 200240，China)
The third-generation synchrotron radiation source can generate high-energy X-rays to realize in-situ non-destructive characterization of the internal crystal structure of engineering materials under service conditions. As an emerging characterization technique based on synchrotron radiation, three-dimensional Xray diffraction (3DXRD) technique uses monochromatic high-energy hard X-rays to collect diffraction signals along different directions from polycrystalline materials to obtain the crystal orientation, spatial position, and local stress tensor of the grains inside the material. When the 3DXRD technique is combined with in-situ experiments, the dynamic evolution of the state of each crystal grain can be obtained. This technique has been successfully implemented in synchrotron radiation facilities such as ESRF in Europe, APS in the United States, SPring8 in Japan and DESY in Germany. This article reviews the working principles of 3DXRD and its applications in engineering materials research, including measuring the evolution of grain orientation in materials, measuring grain-scale stress, studying the deformation mechanisms of hexagonal materials, understanding material failure, and verification of crystal plasticity finite element models. Finally, based on the status of 3DXRD, its development direction is envisioned.