Abstract Scope |
New in situ experimental results are obtained under heterogeneous compression of materials in a diamond anvil cell (DAC) and torsion in rotational DAC (RDAC). Materials under study include carbon, Zr, Si, and olivine. Drastic reductions (by one to two orders of magnitude) of the phase transformation (PT) pressure compared with hydrostatic loading and the appearance of new phases are demonstrated. The four-scale theory for plastic strain-induced PTs is developed, including molecular dynamics and first-principle simulations, developed nanoscale and scale-free phase-field approaches, and the behavior of the sample in DAC/RDAC at the macroscale. Combining in situ experiments with multiscale theory leads to the finding of new rules and quantitative models for severe plasticity, strain-induced PTs, and microstructure evolution, formulation of methods to control strain-induced PT and microstructure evolution, designing economic synthetic paths for the defect-induced synthesis of desired high-pressure phases, nanostructures, and nanocomposites, and resolving puzzles of the deep-focus earthquakes. |