Abstract Scope |
Kinking is a novel deformation mode in systems exhibiting plastic anisotropy. These include geological formations, laminated composites, and layered crystalline solids such as graphite, mica, and MAX phases. It is particularly relevant in the latter, ternary carbides and nitrides, being implicated in some of their unique properties, most notably an ability to dissipate large quantities of mechanical energy. Despite its fundamental relevance to crystal plasticity, an understanding of the mechanisms responsible for kinking has remained elusive for 70+ years. Recently, we have developed interatomic potentials for MAX phases, which now enable simulations at the length and time scales relevant to kinking. Combining these simulations with the deformation of single crystals, we show that kinking arises due to a coupling of atomic layer buckling with concomitant basal dislocation nucleation. Importantly, the latter cannot occur without the former. These results are a fundamental advance in understanding the deformation of crystalline layered solids. |