Polycrystalline materials constitute the majority of metals and alloys. From a microstructural perspective, these materials consist of grains separated by grain boundaries (GBs), which significantly influence material properties. At room temperature, GBs contribute to strengthening through grain refinement, while at elevated temperatures, they exhibit lower strength compared to grain interiors. The presence of additional free volume in GB atomic lattices, compared to grain interiors [1, 2], fundamentally explains their impact on material properties. Research has revealed that GBs possess diverse structures and characteristics, necessitating their classification. The conventional classification system distinguishes between low angle and high angle boundaries, with high angle boundaries further categorized into random boundaries and special boundaries. Special boundaries represent GBs exhibiting distinctive properties or crystal structures.