fracture toughness

Fracture toughness is a measure of a material's resistance to crack propagation. In mechanics, designers aim to prevent failure in structures and machines by estimating anticipated stresses and selecting materials that can withstand them. While conventional stress analysis and material property tests are still used, the focus has shifted to preventing sudden crack propagation rather than general fracture.1

Crack propagation can occur through opening, edge sliding, or tearing. Advanced structural ceramics, while often brittle, can be engineered for improved toughness through methods like microstructural design to deflect cracks, or by incorporating mechanisms like microcracking or phase transformations (e.g., in zirconia) that absorb energy and resist crack growth. Toughened ceramics offer significantly improved fracture toughness compared to conventional ceramics, though they are still less tough than metals.12