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

To reduce reliance on experimental fitting data within the crystal plasticity finite element method, an approach 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 (similar to 0.4) for multiple loading orientations demonstrates a possible route for more predictive crystal plasticity modeling through incorporation of analytical models of mesoscale physics.

Automated summary

A method integrating first-principles calculations is proposed to predict the strain-hardening behavior of pure Ni single crystals. The study found that elastic interactions of pure edge dislocations capture hardening behavior for small strains, while a strain-weighted linear combination of edge and screw flow resistance components captures hardening behavior for larger strains.