A Discrete Model for Diffusion-Induced Grain Boundary Deterioration

Andrey P. Jivkov; John R. Yates

doi:10.4028/www.scientific.net/KEM.592-593.757

Paper Titles

Deformation Behaviour of Asymmetrically Fatigue Cycled Metallic Materials
p.741

An Effect of the First Non-Singular Term of the Williams Asymptotic Expansion to the Stability of the Bi-Material Orthotropic Notch
p.745

Fatigue Crack Growth of Thin Wall Magnesium AZ91 Alloy Cast
p.749

Short Crack Growth Behavior in Ferrite-Bainite Dual Phase Steels
p.753

A Discrete Model for Diffusion-Induced Grain Boundary Deterioration
p.757

Role of Microstructure on Fracture Behavior of T91 Steel in Presence of Liquid Sodium
p.761

Transition from Straight to Fractal Cracks due to Projectile Penetration
p.765

The Effect of Temperature on the Course of Refractory Castables Cracking
p.769

Temporal and Spatial Evolution of Bursts in a Fiber Bundle Model of Creep Rupture
p.773

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A Discrete Model for Diffusion-Induced Grain Boundary Deterioration

Abstract:

Polycrystalline materials may suffer internal damage due to diffusion of chemically aggressive species during service. Diffusion rates are greatly enhanced on grain boundaries (GB). This can be modelled with discrete networks, where the GB structure is represented by links with local diffusivities. We present a site-bond model for concentration-driven diffusion that can be used to study the accumulation of chemical species at GB, leading to deterioration and eventual cracking. We employ realistic distributions of GB energies and corresponding diffusivities from published works. We show how the model can be used to predict macroscopic diffusivities with little experimentation. We demonstrate how the grain boundary structure controls the extent of internal damage resulting from the diffusion of chemical species.