The Earth's Lithosphere Inspires Materials Design

Abstract

Structural patterns found in living organisms have long been inspiring biomimetic materials design. Here, it is suggested that a rich palette of patterns occurring in inanimate Nature, and especially in the Earth's lithosphere, could be not less inspirational for design of novel architectured materials. This materials design paradigm is referred to as lithomimetics and it is demonstrated that some of the patterns found in the lithosphere can be emulated by established processes of severe plastic deformation. This opens up interesting avenues for materials design in which potentially promising structural patterns are borrowed from the lithosphere's repository. The key aim here is to promulgate the “lithomimetics” paradigm as a promising approach to developing novel architectured materials.

Architecturing materials at mesoscale: some current trends

“…In a striking semblance with patterns exemplified by Figure 8, similar characteristic features are also found in specimens of engineering materials deformed to very large shear strains under high pressure [119]. Such processes, collectively labeled severe plastic deformation (SPD) [123], have become popular as a means of achieving outstanding mechanical properties of metallic materials through extreme grain refinement [124].…”

“…We now turn to a very recent new approach to design of architectured materials, referred to as lithomimetics, which was recently proposed in [119]. Although the types of the mesoscale structures it operates with may resemble those also considered in other materials design strategies, there is a defining principle that distinguishes lithomimetics from other approaches.…”

“…What makes metallic SPD-derived materials with expressly lithomimetic architecture (LA) particularly attractive? While the full picture is not yet clear, one can dare the assertion that the components of LA materials will have an ultrafine grain structure-a hallmark of SPD [119,[133][134][135][136].) In all figures, the harder of the two constituent layers is shown in green.…”

“…Schematics of several characteristic elements of lithomimetic structures induced by HPT of assemblies of stacked alternating layers of two different metals: (a) initial structure, (b) folds, (c) vortices, (d) boudinage, (e) fine lamellar structure, (f) vortex in a fine lamellar structure. (Adapted from Refs [119,[133][134][135][136]…”

Turbulent shear flow of solids

“…Investigations of SST as a stochastic nonlinear phenomenon is of great scientific significance, as it has certain universality and can occur at different length scales: from laboratory experiments to processes in the Earth's lithosphere [20]. The phenomenon is also of practical importance, as SST opens an avenue for solid-state mixing and physicochemical reactions under high pressure, whose potentialities in materials engineering can hardly be overestimated [13,21].…”