|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Atom Probe Tomography for Advanced Characterization of Metals, Minerals and Materials
||Spinodal Decomposition and Periodic Segregation in Grain Boundaries on Al Alloy
||Huan Zhao, Dirk Ponge, Baptiste Gault , Agnieszka Szczepaniak, Dierk Raabe
|On-Site Speaker (Planned)
Understanding the chemistry and structure evolution of grain boundary precipitates at atomic scale in aluminum alloys is crucial, if we want to properly tailor grain boundary precipitation and avoid formation of precipitation free zones to achieve desired mechanical properties. Here, using atom probe tomography and in-situ scanning transmission electron microscopy on Al-Zn-Mg-Cu alloy, we elucidated the kinetics of grain boundary precipitation: spinodal decomposition into solute-rich in the grain boundary and solute depletion in the bulk, nucleation of nanoclusters within the solute-rich region, followed by growth of these nanoclusters. The spinodal decomposition lead to the nucleus formation and growth of grain boundary precipitates happening much faster than in the bulk. Furthermore, we report equilibrium segregation of solute atoms to ordered defects within an individual coincident site lattice (CSL) grain boundary. This periodic segregation could add important information on the different segregation phenomena on CSL and random grain boundaries in aluminum alloys.
||Planned: Supplemental Proceedings volume