Stabilization and Strengthening of Nano-Crystalline Materials by Alloying
Abstract
The goal of the project was to advance the fundamental understanding of the thermodynamic and kinetic mechanisms of grain stabilization in nano-materials. The model systems chosen for this project are Cu-Ta alloys stabilized by Zener pinning of grain boundaries (GBs) (kinetic mechanism), and Cu-Bi alloys stabilized by reduction of the GB free energy (thermodynamic mechanism). A wide range of atomistic computer simulation methods were applied to investigate the thermodynamics and kinetics of GBs in the chosen alloys and the effect of GB segregation on their mechanical behavior. This required the development of a new interatomic potentials and computationally efficient algorithms for GB free energy calculations in the high-throughput mode. The simulations were performed on both polycrystalline samples, representing collective behavior of multiple GBs, and on individual, crystallographically characterized boundaries. In the latter case, the goal was to establish a link between GB structure, bicrystallography, and thermodynamic and kinetic factors of thermal stability. This project contributed to the fundamental knowledge base needed for the optimization of synthesis and processing routes and discovery of new thermally stable nanocrystalline alloys. This research was synergistic with experimental work on stabilized nanocrystalline alloys conducted at the Army Research Laboratory.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 03, 2023
- Accession Number
- AD1223023
Entities
People
- Y. Mishin
Organizations
- George Mason University