  Computing the grain boundary (GB) counterparts to bulk phase diagrams
represents an emerging research direction. Using a classical embrittlement
model system Ga-doped Al alloy, this study demonstrates the feasibility of
computing temperature- and composition-dependent GB diagrams to represent not
only equilibrium thermodynamic and structural characters, but also mechanical
properties. Specifically, hybrid Monte Carlo and molecular dynamics (MC/MD)
simulations are used to obtain the equilibrium GB structure as a function of
temperature and composition. Simulated GB structures are validated by
aberration-corrected scanning transmission electron microscopy. Subsequently,
MD tensile tests are performed on the simulated equilibrium GB structures. GB
diagrams are computed for not only GB adsorption and structural disorder, but
also interfacial structural and chemical widths, MD ultimate tensile strength,
and MD tensile toughness. This study suggests a research direction to
investigate GB composition-structure-property relationships via computing GB
diagrams of thermodynamic, structural, and mechanical (or potentially other)
properties.
