Training-induced criticality in martensites

TL;DR

This paper explains how martensites self-organize into a critical state during cyclic training, driven by phase transformations and lattice defects, modeled through a dynamical system that reproduces key experimental observations.

Contribution

It introduces a novel dynamical model linking phase transformation and defect activity to criticality in martensites, capturing experimental phenomena.

Findings

Reproduces power-law statistics in martensite behavior

Models hysteresis shakedown and asymmetric signals

Shows correlated disorder consistent with experiments

Abstract

We propose an explanation for the self-organization towards criticality observed in martensites during the cyclic process known as `training'. The scale-free behavior originates from the interplay between the reversible phase transformation and the concurrent activity of lattice defects. The basis of the model is a continuous dynamical system on a rugged energy landscape, which in the quasi-static limit reduces to a sandpile automaton. We reproduce all the principal observations in thermally driven martensites, including power-law statistics, hysteresis shakedown, asymmetric signal shapes, and correlated disorder.