Stress-assist chemical reactions front propagation in deformable solids

A.B. Freidin,I.K. Korolev,E.N. Vilchevskaya

doi:10.1016/j.ijengsci.2014.03.008

A.B. Freidin, I.K. Korolev + Show 1 more

Open Access

https://doi.org/10.1016/j.ijengsci.2014.03.008

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Abstract

We consider a stress-assist chemical reaction front propagation in a deformable solid undergoing a localized chemical reaction between solid and gas constituents. The reaction is sustained by the diffusion of the gas constituent through the transformed solid material. The transformation strain produced by the chemical reaction lead to internal stresses which in turn affect the chemical reaction front kinetics. Basing on the notion of the chemical affinity tensor we formulate a kinetic equation in a form of the dependence of the front velocity on the normal component of the chemical affinity tensor. As an example we consider a planar chemical reaction front propagation in an elastic plate subjected to uniaxial tension or compression. We demonstrate the possibility of the locking effects – blocking the reaction by stresses at the reaction front. We study in details how the velocity of the chemical reaction front and the locking effect depend on chemical reaction parameters and external loading.

Highlights

The influence of mechanical loading on chemical reaction kinetics remains to be of significant interest for both fundamental and applied engineering science
As a result we obtain an expression of the chemical affinity tensor as a combination of Eshelby stress tensors of the solid constituents and a chemical potential of a gas constituent [10]
We say that the gas concentration is equilibrium at the reaction front if, given temperature, front position and stresses, the chemical affinity is equal to zero. This allows us to formulate a kinetic relationship for the reaction front velocity in terms of current gas concentration at the reaction front and equilibrium concentration that depends on stresses at the front

Summary

Introduction

The influence of mechanical loading on chemical reaction kinetics remains to be of significant interest for both fundamental and applied engineering science. We say that the gas concentration is equilibrium at the reaction front if, given temperature, front position and stresses, the chemical affinity is equal to zero.

Results

Conclusion