부산대학교 도서관

In this study, we examine the role of relatively large amounts of intragranular lattice misorientation - present after many thermomechanical processes - through three-dimensional (3D) micromechanical simulations of forged Al-7085 with a modified T7452 temper. We utilize near-field high-energy X-ray diffraction microscopy (HEDM) to measure 3D spatial orientation fields, and employ a novel reconstruction method that utilizes grain orientation envelopes measured using far-field HEDM to enable reconstruction of grains with intragranular orientation spreads >10{\deg}. We construct two primary virtual polycrystalline specimens for use in crystal plasticity simulations to assess the effect of appreciable intragranular misorientation on the predicted deformation response: the first a faithful representation of the HEDM reconstruction, the second a microstructure with no intragranular misorientation (i.e., grain-averaged orientations). We find significant differences in the predicted deformation mechanism activation, distribution of stress, and distribution of plastic strain between simulations containing intragranular misorientation and those with homogenized orientations. The influence of elastic anisotropy is discussed, along with the effects of intragranular misorientation on fatigue life through the calculation and analysis of fatigue indicator parameters.