Modeling of resistance curve of high-angle grain boundary in Fe–3 wt.% Si alloy

When a propagating cleavage front encounters a high-angle grain boundary it first penetrates through the grain boundary stably. With increasing penetration depth the resistance of the grain boundary rises, resulting in the well-known R-curve. When the balance between the rates of the energy release rate and the grain boundary resistance is reached, the crack advance becomes unstable and the grain boundary is broken through. In this paper, this process is analyzed quantitatively based on the experimental observations of the cleavage cracking in Fe–3 wt.% Si bicrystals. The effects of the crystal misorientation, the crack length, and the crack front profile are discussed.