Spatially resolved strain measurements in Mo-alloy micropillars by differential aperture x-ray microscopy

Spatially resolved strain distributions in the NiAl matrix and the similar to 550-1000 nm Mo fibers of a NiAl-Mo eutectic were investigated by microbeam x-ray diffraction. Position sensitive d-spacings for the individual phases were obtained from spatially resolved and energy-resolved Laue patterns. For embedded Mo fibers, the measured elastic strain is consistent with the predicted thermal mismatch strain between the NiAl and Mo phases. However, when the NiAl matrix is etched back to expose Mo micropillars, the d-spacing increases to that of unconstrained Mo, indicating release of the compressive residual strain in the Mo fibers. (c) 2008 American Institute of Physics.