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Abstract: Polychromatic microdiffraction uses small X-ray beams to characterize the local crystallographic structure of materials. When combined with a depth resolving technique called differential aperture microscopy, the phase and local orientation of femto-liter volumes (0.5×0.5×0.7μm3) can be resolved beneath the surface of a sample. In addition, the local elastic strain and dislocation tensors can also be determined and the local dislocation type can be modeled. Here we present recent technical developments, including example applications and emerging research directions. [Copyright &y& Elsevier]

The depth-dependent strain gradients near buried interfaces in a model system of NiAl–Mo composite were nondestructively probed with 3-D X-ray microdiffraction. Coupled with micromechanical analysis, our study shows that the relaxation of the residual thermal strains in the NiAl–Mo composites results in the formation of a near-surface “slip zone” with large strain gradients in both the reinforcing Mo fibers and NiAl matrix. Based on these results an approach to calculate the fiber–matrix interface strength for composite materials is suggested. [ABSTRACT FROM AUTHOR]