| Abstract Scope |
Grain boundaries (GBs) can be considered as 2-D interfacial phases that are also called “complexions” to differentiate them from bulk Gibbs phases. In this talk, I will first review a series of our studies to compute GB “phase” (complexion) diagrams via interfacial thermodynamic models [see, e.g., APL 92:101901 (2008), Current Opinion 2:81 (2008) & 20:268 (2016), PRB 84:014105 (2011), JACerS 95:2358 (2012), Acta 91:202 (2015) & 130:329 (2017), and Scripta 130:165 (2017)], hybrid molecular dynamics (MD) and Monte Carlo (MC) atomistic simulations [PRL 120:085702 (2018) and Scripta 158:11 (2019)]] and (most recently) machine learning. Second, recent observations of GB complexions in two classical GB embrittlement systems, Ni-Bi [Science 333:1730 (2011) & 358:97 (2017)] and Ni-S [Nature Comm. 9:2764 (2018)], will also be discussed. Third, I will discuss our recent studies to successfully stabilize nanocrystalline alloys at high temperatures (>1000 C) via utilizing high-entropy GBs [Scripta 124:160 (2016) and beyond]. |