Recent progress in the application of rotational diamond anvil cell

Abstract

The combination of high pressure and severe plastic deformation in the process of high-pressure torsion in a rotational diamond anvil cell (RDAC) produces a variety of important mechanical and chemical effects. In this Review, mechanochemical phenomena that appeared with compression and plastic shear of samples in RDAC have been systematized, which are associated with strain-induced structural changes (SCs) under high pressure and shear, containing phase transitions (PTs) and chemical reactions (CRs). This Review aims to summarize the current phenomena based on the results of multiscale atomic and continuum theory and macroscale modeling. By analyzing and using the advanced phase field theory and simulation, the nano-scale mechanism of phase nucleation induced by plastic strain was studied. The results show that the concentration of the stress tensor near the edge dislocation stacking tip may reduce the nucleation pressure by ten times or more. These results promote the development of a microscopic analysis dynamic equation of strain-induced PTs. On the micro-scale, a simple strain control dynamic kinetics of strain-induced SCs is derived by thermodynamics. On the macro-scale, a macro-model of pressure and strain-induced PTs in RDAC is established based on the finite element method, and it could be used to explain various experimental phenomena. The application of RDAC provides important insights for the coupling of PT and material plastic flow, which is of great significance for optimizing the experimental design and extracting PT parameters of materials, as well as optimizing and controlling PT.