Rotation-limited growth of three dimensional body-centered cubic crystals

TL;DR

This paper investigates the coarsening behavior of 3D body-centered cubic crystals, revealing a transition between halted grain rotation and rapid coarsening driven by lattice alignment, with results supported by phase field crystal modeling.

Contribution

It introduces a phase field crystal model study showing a crossover in grain growth behavior influenced by lattice anisotropy and rotation dynamics.

Findings

Grain rotation follows a power law with exponent -1.25.

A crossover exists between halted rotation and rapid coarsening.

Results align with dislocation conservation theory.

Abstract

According to classical grain growth laws, grain growth is driven by the minimization of surface energy and will continue until a single grain prevails. These laws do not take into account the lattice anisotropy and the details of the microscopic rearrangement of mass between grains. Here we consider coarsening of body-centered cubic polycrystalline materials in three dimensions using the phase field crystal model. We observe as function of the quenching depth, a cross over between a state where grain rotation halts and the growth stagnates and a state where grains coarsen rapidly by coalescence through rotation and alignment of the lattices of neighboring grains. We show that the grain rotation per volume change of a grain follows a power law with an exponent of $-1.25$. The scaling exponent is consistent with theoretical considerations based on the conservation of dislocations.