About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
|
| Presentation Title |
Influence of Grain Boundary Energy on the Complexion Transition at Grain Boundaries in Au-Pt Alloys |
| Author(s) |
Wen-Yu Chen, Elizabeth Dickey, Maarten De Boer, Gregory S. Rohrer |
| On-Site Speaker (Planned) |
Wen-Yu Chen |
| Abstract Scope |
A reversible grain boundary complexion transition, from stoichiometric boundaries at 300 °C to Au-enriched boundaries at 500 °C has been reported for Au1-xPtx (x = 0.15 to 0.18) alloys. The results also showed that not all grain boundaries transform at the same temperature. It is hypothesized that the grain boundaries with the largest energies transform preferentially (and might be transformed at 300 °C) while the lowest energy grain boundaries resist transformation, even at the highest temperatures. To test this hypothesis, correlative microscopy was used to connect orientation maps and composition maps. Grain boundary energies were assigned based on an interpolation of molecular dynamics calculations and grain boundary excess was determined from energy dispersive spectroscopy data. Based on the analysis of 70 grain boundaries annealed at 500 °C, boundaries transformed to the Au-enriched state are more likely to have higher energies than those that are untransformed. |