Kinetics of propagating phase transformation in compressed bismuth

TL;DR

This paper investigates the dynamics of phase transformations in compressed bismuth, distinguishing between boundary-initiated and bulk-front transformations, and introduces a coupled model to extract transition times from experiments.

Contribution

It presents a coupled kinetics-hydrodynamics model that allows direct extraction of transition times for propagating phase fronts in compressed bismuth.

Findings

Identified two distinct phase transformation mechanisms in compressed bismuth.

Developed a model enabling direct measurement of transformation times.

Provided experimental evidence of phase boundary dynamics.

Abstract

We observed dynamically driven phase transitions in isentropically compressed bismuth. By changing the stress loading conditions we explored two distinct cases: one in which the experimental signature of the phase transformation corresponds to phase-boundary crossings initiated at both sample interfaces, and another in which the experimental trace is due to a single advancing transformation front in the bulk of the material. We introduce a coupled kinetics - hydrodynamics model that for this second case enables us, under suitable simplifying assumptions, to directly extract characteristic transition times from the experimental measurements.