A Model for Phase Transitions Under Dynamic Compression

Abstract

An approach is described for simulating phase transitions among an arbitrary number of phases under dynamic compression. The time evolution of the phase fractions k i is governed by the master equation, which naturally incorporates the constraints P i k i ¼ 1 and 0 k i 1. The rates are taken to be strongly nonlinear functions of the thermodynamic driving forces. The implementation of the method is described, and illustrative applications to phase transitions in Zr are shown. The relation of the model to irreversible thermodynamics is discussed. A modification for the case where domain growth limits the transformation rate is described. This variant gives sigmoidal transformation-time curves, with the second phase fraction proportional to t 3 at early time.

Rapid freezing of water under dynamic compression

“…A model that includes a dependence of the driving force squared is that of Greeff [73], which presents a variation of the Boettger and Wallace model of the form…”

A Multi-Phase Modeling Framework Suitable for Dynamic Applications

“…For example, Ref. [34] has developed a model and implementation algorithm for the rate of transformation between constituent phases which can be used to define the irreversible evolution of phase fractions. It is also possible to include physical effects such as nucleation and growth in the kinetics model, and models with such effects have been used to examine pressure-driven solidification [35].…”

Celebrating 75 Years of the Society for Experimental Mechanics and the Study of Dynamic Behavior of Materials

“…The journal is highly international, publishing experimental and theoretical studies of metals [57], polymers [58], glasses [59], composites [60], granular materials [61], explosives [62], biological materials [63], geological materials [64], phase transitions [65], and structural response [66]. The journal includes application and development of techniques including split Hopkinson pressure bar/Kolsky bar [67], plate impact with light gas guns and powder guns [68], Taylor Anvil [69], Dynamic-TensileExtrusion [70], spectroscopy-and pyrometry-based shock temperature measurements [71], optical and X-ray imaging methods [72], interferometry and velocimetry techniques [73], dynamic fracture [74], laser based dynamic drivers [75], penetration and ballistics [76], equation of state [77], and spall failure [78].…”