Predictive Crystal Plasticity Modeling of Single Crystal Nickel Based on First-Principles Calculations

Abstract

To reduce reliance on experimental fitting data within the crystal plasticity finite element method (CPFEM), an approached is proposed that integrates first-principles calculations based on density functional theory (DFT) to predict the strain hardening behavior of pure Ni single crystals. Flow resistance was evaluated through the Peierls-Nabarro equation using the ideal shear strength and elastic properties calculated by DFT-based methods, with hardening behavior modeled by imposing strains on supercells in first-principles calculations. Considered alone, elastic interactions of pure edge dislocations capture hardening behavior for small strains on single slip systems. For larger strains, hardening is captured through a strain-weighted linear combination of edge and screw flow resistance components. The rate of combination is not predicted in the present framework, but agreement with experiments through large strains (~0.4) for multiple loading orientations demonstrates a possible route for more predictive crystal plasticity modeling through incorporation of analytical models of mesoscale physics.