|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Deformation and Transitions at Interfaces
||Alloy Stabilization of Nanocrystalline Grain Structures: Case Study of Pt-Au
||Stephen M. Foiles, Christopher J. O'Brien, Ping Lu, Michael E. Chandross, Nicholas Argibay, Brad L. Boyce
|On-Site Speaker (Planned)
||Stephen M. Foiles
Nanocrystalline metals have desirable properties, but the grain microstructure is often insufficiently stable for engineering application. One route to stabilize the grain structure is alloying which can be imagined to have three broad effects: Zener pinning of boundaries by precipitates, the reduction of grain boundary energy due to segregation and the reduction of grain boundary mobility due to solute-boundary interactions. Here we will examine these potential influences for the model alloy platinum-gold. Off-lattice Monte Carlo simulations of the equilibrium segregation at both select bi-crystal boundaries and in nanoscale polycrystals predict the variability in segregation levels. Molecular dynamics simulations determine the response of select boundaries and grain microstructures to both thermodynamic driving forces and mechanical stresses. The atomistic predictions will be compared to electron microscopy experimental observation and quantification of the segregation during thermal annealing of platinum-gold thin films.