Zhao Huan, Huber Liam, Lu Wenjun, Peter Nicolas J, An Dayong, De Geuser Frédéric, Dehm Gerhard, Ponge Dirk, Neugebauer Jörg, Gault Baptiste, Raabe Dierk
Max-Planck-Institut für Eisenforschung, Max-Planck-Straβe 1, 40237 Düsseldorf, Germany.
Université Grenoble Alpes, CNRS, Grenoble INP, SIMaP, F-38000 Grenoble, France.
Phys Rev Lett. 2020 Mar 13;124(10):106102. doi: 10.1103/PhysRevLett.124.106102.
The boundary between two crystal grains can decompose into arrays of facets with distinct crystallographic character. Faceting occurs to minimize the system's free energy, i.e., when the total interfacial energy of all facets is below that of the topologically shortest interface plane. In a model Al-Zn-Mg-Cu alloy, we show that faceting occurs at investigated grain boundaries and that the local chemistry is strongly correlated with the facet character. The self-consistent coevolution of facet structure and chemistry leads to the formation of periodic segregation patterns of 5-10 nm, or to preferential precipitation. This study shows that segregation-faceting interplay is not limited to bicrystals but exists in bulk engineering Al alloys and hence affects their performance.
