Numerical Exploration of Thermal Shock Resistance in MgO–C Refractories

Refractories are polycrystalline, porous, nonmetallic materials used as protective liners in high‐temperature manufacturing. During service, rapid temperature changes generate stresses from temperature gradients and thermal expansion mismatches, leading to crack initiation and propagation, making thermal shock resistance (TSR) a critical property. TSR is strongly influenced by mesostructural features such as aggregate size distribution, phase volume fractions, aggregate–matrix interface properties, and toughening mechanisms, making its evaluation challenging. While analytical and experimental methods exist, numerical approaches remain limited. This study computationally evaluates TSR in MgO–C refractories using a 2D plane‐strain model of a laboratory‐scale brick, represented as a three‐phase composite of MgO aggregates, graphite flakes, and an effective matrix. A thermo‐mechanically coupled cohesive zone model captures interface debonding during thermal shock. A modified TSR parameter incorporating initial crack length and crack density is introduced, providing a mesostructure‐sensitive and physically interpretable measure of TSR in the computational assessments. Thermal shock simulations are performed, with varying graphite volume fractions and aggregate size distributions, and results are compared with classical TSR parameters, demonstrating improved sensitivity of the proposed approach to mesostructural effects. This framework enables computational exploration of mesostructure–property relations in refractories where interface debonding influences TSR, supporting materials development by identifying promising design targets.