Transformational process zone emerging at the tip of a propagating crack

TL;DR

This paper presents a theoretical study of a process zone at a crack tip caused by a local phase transition, analyzing its existence conditions, boundary, and dependence on crack velocity.

Contribution

It introduces a theoretical framework for understanding the formation and limits of a phase transition-induced process zone at crack tips.

Findings

The process zone exists only within specific regions of the phase diagram.

A critical crack velocity exists beyond which the zone cannot form.

Numerical solutions complement the analytical results far from the bifurcation point.

Abstract

Process zone at the tip of a propagating crack engendered by the stress-induced local phase transition of the second order is studied theoretically. We show that the zone can only exist within a certain domain of the phase diagram at one side of the phase transition line depending upon the sign of the striction constant. We obtain the boundary of this domain and establish its dependence upon the crack velocity. We show the existence of a critical crack velocity above which the zone cannot exist. We report the overcritical solution for the order parameter describing the incipient process zone, while far from the bifurcation point we solve the problem numerically.