Zener pinning

Zener pinning is the influence of a dispersion of fine particles on the movement of low- and high-angle grain boundaries through a polycrystalline material.

Zener pinning is very important in materials processing as it has a strong influence on recovery, recrystallization and grain growth.

In order to move past the particle some new boundary must be created, and this is energetically unfavourable.

The figure illustrates a boundary intersecting with an incoherent particle of radius

The pinning force acts along the line of contact between the boundary and the particle, i.e., a circle of diameter

In order to determine the pinning force resulting from a given dispersion of particles, Clarence Zener made several important assumptions: For a volume fraction,

If the boundary is essentially planar, then this fraction will be given by Given the assumption that all particles apply the maximum pinning force,

[1] Particle pinning has been studied extensively with computer simulations, such as Monte Carlo and phase field methods.

These methods can capture interfaces with complex shapes and provide better approximations for the pinning force.

- "Contribution à l'étude de la dynamique du Zener pinning: simulations numériques par éléments finis", Thesis in French (2003).

- "3D finite element simulation of the inhibition of normal grain growth by particles".