About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
|
| Presentation Title |
A First Principles Study on the Role of Grain Boundaries in the Oxidation of Refractory Metals |
| Author(s) |
Colin Mclagan, Adib Samin |
| On-Site Speaker (Planned) |
Colin Mclagan |
| Abstract Scope |
Refractory alloys present new opportunities for high strength, temperature resistant material applications. However, they are generally susceptible to high temperature oxidation. In this work, we seek to elucidate the mechanisms of oxidation in grain boundaries (GB) of differing misorientation angles and GB energies. In particular, we utilize density functional theory computations to examine oxygen thermodynamics in the GB. Using grand canonical Monte Carlo simulations, we study the buildup of oxygen in the GB region with changing temperature and oxygen potential, allowing us to establish local phase diagrams for different GBs. Selecting GB structures with various oxygen concentrations, we study the effect of oxidation on GB strength. Lastly, we determine the segregation tendencies of substitutional solutes and analyze their influence on the oxidation and strength of the GB. Establishing these defect phase diagrams and structure-property relationships can help inform the design of next generation structural materials for extreme environments. |