Crystal Plasticity Assessment of Texture Discretization and Lamellar Grain Morphology for Predicting the Anisotropic Behavior of LPBF IN718

The anisotropic mechanical behavior of laser powder bed fused (LPBF) IN718 results from the combined effects of crystallographic texture and grain morphology, although their individual contributions remain difficult to quantify. In this work, six representative volume elements (RVEs) are systematically compared using a unified EBSD–Dream3D–DAMASK crystal plasticity framework to separate the effects of texture and morphology. The microstructures include two EBSD-derived RVEs, two discretized columnar RVEs, and two discretized lamellar RVEs generated from identical orientation distributions. Predicted elastic moduli and yield strengths are validated against experiment, while Taylor factor analysis, directional effective grain size, slip compatibility, KAM, and local crystal plasticity fields are used to identify the governing deformation mechanisms. The results show that crystallographic texture predominantly controls the elastic response, whereas grain morphology governs the onset of plastic deformation. Lamellar RVEs provide the closest agreement with the experimental yield-strength anisotropy by reproducing the directional effective grain size, the connectivity of mechanically hard domains, and the resulting redistribution of stress and plastic strain. Furthermore, texture discretization preserves the dominant anisotropic trends while substantially reducing the computational cost of full EBSD reconstructions, establishing an efficient and physically meaningful framework for crystal plasticity simulations of LPBF materials.