Abstract Scope |
Grain boundary behavior has been studied up to date due to its complex behavior; acts as a sink or a source, low-angle grain boundaries allowing dislocation transmission, etc. In this study a columnar-like aluminum sample with large grain sizes reaching over millimeters was fully characterized by using EBSD technique from the two opposite side surfaces. The sample was tensile tested and strains were measured using DIC method. To better understand grain boundary effects, crystal-based finite element models with three different constitutive laws were developed including a phenomenological model, dislocation density based model and a non-local flux based dislocation density model. The amount of grain boundary strengthening was found to be a function of the amount of slip inside grains, misorientation between the grains, and grain boundary normal. Non-local dislocation flux based model revealed significantly better strain distributions near the grain boundary, even though the sample scale was relatively large. |