| About this Abstract |
| Meeting |
Materials Science & Technology 2011
|
| Symposium
|
Advanced Protective Coatings for Refractory Metals and Alloys
|
| Presentation Title |
ReaxFF Reactive Force Field for Molecular Dynamics Simulations of Niobium Oxidation |
| Author(s) |
De Nyago Tafen, Adri C. T. Van Duin, Michael Gao, Jeffrey Hawk |
| On-Site Speaker (Planned) |
De Nyago Tafen |
| Abstract Scope |
Lack of adequate oxidation resistance is the major obstacle to applying Nb-based alloys for advanced gas turbine technologies at T>1200 <SUP>o</SUP>C. In order to gain fundamental understanding of oxidation mechanisms of Nb alloys, we have performed molecular dynamics to predict oxygen adsorption dynamics and surface oxide formation. A new ReaxFF force field is developed to describe the chemical events associated with oxidation of niobium at high temperatures. The parameters in ReaxFF were derived directly from quantum mechanics calculations and were validated to provide reasonable accuracy for a wide variety of structures, energetics and reactions. Our ReaxFF describes accurately the energetics of various oxides including Nb<SUB>2</SUB>O<SUB>5</SUB>, NbO<SUB>2</SUB>, and NbO, and Nb. Based on our ReaxFF, we have used LAMMPS to simulate oxygen absorption, oxygen ion transport, oxidation formation in presence of oxygen gas exposed to various surfaces including (011) plane of niobium. Comparison between simulations with experiments will be presented. |
| Proceedings Inclusion? |
Definite: A CD-only volume |