Measuring Depth-dependent Dislocation Densities and Elastic Strains in an Indented Ni-based Superalloy

The indentation-induced elastic-plastic zone in an IN 740 Ni-based superalloy was studied by three-dimensional (3-D) x-ray microdiffraction and electron back scattering diffraction (EBSD). Large lattice reorientations and the formation of geometrically necessary dislocations are observed in the area with a radius of ∼75 μm. A residual compression zone is found close to the indent edge. An elastic-plastic transition is observed at ∼20 μm from the indent edge. Depth dependent dislocation densities are determined at different distances from the indent edge.