Grain boundary velocity and curvature are not correlated in Ni polycrystals

Revising grain growth Polycrystalline materials will often coarsen during annealing, a process that can modify the physical properties. A generally accepted theory ties the grain boundary curvature to the velocity at which grain boundaries migrate. Bhattacharya et al . measured this relationship for 52,000 grains in a nickel sample. They did not observe any relationship between curvature and velocity, suggesting that this accepted theory is not robust for polycrystalline samples. The observations require grain-coarsening models to be updated to more accurately predict the effects of annealing. —BG