Effect of elastic anisotropy on strain relief and residual stress determination in cubic systems by FIB-DIC experiments

Focused Ion Beam milling and Digital Image Correlation analysis (FIB-DIC) method has been shown to offer an effective measure of residual stresses in coatings and bulk materials. In the present work the effect of elastic anisotropy on the residual stress interpretation from FIB-DIC measurements is studied for single crystals with cubic symmetry. Crystal orientation-dependent, elastically anisotropic 3D finite element models of the double slot milling geometry were developed and verified against FIB-DIC measurements performed on in situ four point bent samples of nanocrystalline nickel and single crystal CMSX-6 alloy. A discussion is presented of the limitations of the simplified assumptions vs full anisotropic modelling. (C) 2016 Elsevier Ltd. All rights reserved