Abstract Scope |
This talk reviews several studies focusing on general GBs. A series of our earlier studies have developed the GB counterparts to the bulk phase diagrams. Here, a grand challenge is that general GBs has five macroscopic (crystallographic) degrees of freedom (DOFs). A recent collaborative study uses genetic algorithm-guided deep learning to predict GB properties in a 7D space (5 macroscopic DOFs plus temperature and composition) [Materials Today 2020]. Furthermore, several studies investigate general GBs randomly selected from polycrystals, including two classical GB embrittlement systems: Bi [Science 2011 and 2017] vs. S [Nature Comm. 2018] doped Ni. A more complex GB superstructure with highly asymmetric segregation and interfacial reconstruction is discovered in Ti-doped WC-Co [Materials Horizons 2020]. Here, thermodynamic models, DFT calculations, atomistic simulations, machine learning, and advanced microscopy are often combined to understand the complex general GBs. Liquid metal embrittlement and corrosion will be also discussed as examples. |