Abstract
The 3D depth-dependent distribution of indentation-induced strain partitioning through the interfaces between both phases of the NiAl/Mo composite are directly measured at submicron length-scale using X-ray microdiffraction and compared to the micromechanical stress analysis. It is shown that indentation-induced deformation in the composite materials is distinct from single-phase materials because there are distinct residual thermal strains in both phases of the composite in the as-grown state. Interplay between residual thermal strains and external mechanical strain causes nonmonotonic distribution of dilatational strain in Mo fibers and NiAl matrix and is distinct in different locations within the indented area. Reversal of the strain sign (e.g., alternating tensile/compressive/tensile strain distribution) is observed in the NiAl matrix. Bending of the Mo fibers during indentation creates relatively large ~1.5 misorientations between the different fibers and NiAl matrix. Compressive strain along the <001> direction reached the value -0.017 in the Mo fibers and -0.007 in the NiAl matrix.
