Grain Boundary

Metallurgy Fundamentals

Определение

The interface between two adjacent crystal grains of different orientations within a polycrystalline metal. Grain boundaries act as barriers to dislocation motion and significantly influence mechanical, diffusion, and corrosion properties.

Подробное объяснение

The Hall-Petch relationship describes the increase in yield strength with decreasing grain size: σ_y = σ₀ + k/√d, where d is the average grain diameter. Grain refinement is one of the few strengthening mechanisms that simultaneously improves both strength and toughness, making it a preferred approach in modern high-strength steel and microalloyed steel development. At high temperatures, grain boundaries become diffusion pathways and can lead to creep and grain boundary sliding.