The topologies of contacting grains in two and three dimensions

• We simulate 3D normal grain growth in large scale with Monte Carlo method.
• We conduct serial sectioning experiment to get topological data of 3D grains.
• The increase in dimension has dampening effect on affinity of contacting grains.
• The affinity properties in genuine 2D system and 3D one are different.

The topologies of contacting grains were investigated based on large grain datasets from 2D and 3D Monte Carlo simulation, 3D reconstruction of pure iron, and the cross sections of these 3D microstructures. In all systems, the results show the expected trends of high affinity for contact between few- and many-faced or edged grains and avoidance of contact between grains in similar face or edge classes. However, this correlation appears relatively stronger in genuine 2D system than in 2D cross-sectional system and 3D system. This result indicates that the increase in dimension has dampening effect on the contact affinity of curvature-driven grain-growth structure.