Numerical investigation of grain misorientations at and close to the free surface of FCC polycrystalline metals

摘要: Abstract The evolution of grain misorientations (also called orientation gradients) at and close to the free surface polycrystalline aggregates under tensile straining is analyzed within crystal plasticity finite element model. misorientation defined as an angle change with respect average orientation. study based on austenitic stainless steel (300 series) may be in future extended other face-centered-cubic metals. model calibrated single 316 stress–strain curves measured three directions [0 0 1], [1 1 1] [1 2 3]. A procedure for automatic identification material parameters introduced. then used simulations using Voronoi topologies grains random crystallographic orientations. Mean median are calculated a compared electron backscatter diffraction (EBSD) measurements 304 taken from literature. linear correlation between mean/median imposed macroscopic plastic strain found excellent agreement measurements. Furthermore, sensitivity analysis performed, showing that response influenced mostly by in-plane anisotropy much less bulk effects. contributing thickness limited only about below surface. Among various uncertainties assessed, variation topology (different structures) shown have biggest influence misorientations. Finally, sharp 40% decrease predicted when half (or more) size (few 10 μm steel) removed surface, highlighting possibly important sample preparation (e.g., polishing) interpretation obtained sensitive techniques.