‘Turbulent’ shear flow of solids under high-pressure torsion

ABSTRACT

The term ‘solid-state turbulence’ may sound like an oxymoron, but in fact it is not. In this article, we demonstrate that ‘solid-state turbulence’ may emerge owing to a defining property of the solid state: the ability of a solid to retain its shape. We consider shear flow under high-pressure torsion of layers of solids with different flow stress and show that the stiffer ones may spontaneously decompose into a set of blocks. This effect is fundamental for the occurrence of ‘solid-state turbulence’ (SST). To visualize SST, we use a heuristic model based on discretization of a continuum into interacting ‘particles’. The outcomes of the numerical experiments conducted support the occurrence of pulsations of velocity and pressure in plastically deforming solids and the emergence of vortices characteristic of classical turbulence. This phenomenon may have important practical implications for solid-state mixing as an ecologically beneficial alternative to conventional metallurgical processing routes.

KEYWORDS:

• High-pressure torsion
• laminate
• shear flows
• mixing
• turbulence
• moveable cellular automata

Acknowledgements

Funding received from The Volkswagen Foundation through the Cooperation Project Az. 97751 is gratefully appreciated. YB acknowledges support from Karlsruhe Institute of Technology through a visiting fellowship. He also acknowledges funding received from the European Federation of Academies of Sciences and Humanities within the framework of the ‘European Fund for Displaced Scientists’ (Grant reference number of EFDS-FL2-05).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Karlsruher Institut für Technologie, European Federation of Academies of Sciences and Humanities [grant number EFDS-FL2-05], and the Volkswagen Foundation [Cooperation Project Az. 97751].