ABSTRACT
Fracture in brittle materials occurs by simple separation of the specimen (or component) into two or more pieces. At the microscopic level, a type of brittle fracture known as cleavage fracture occurs by crack propagation along the preferred crystallographic planes. For example, in ferritic steels, which have a body-centered cubic structure, cleavage fracture occurs by crack propagation along the (100) planes. A second type of brittle fracture occurs by microvoid coalescence and is common among high-strength aluminum alloys, which have a face-centered cubic structure. The common characteristic among all brittle fractures is the low fracture toughness and a sudden unstable fracture that is catastrophic in structural components. A single fracture toughness value is sufficient for characterizing both types of brittle fractures.
