— It has been recognised since 1850 that a metal part subjected to a repetitive or fluctuating stress will fail at a stress much lower than that required to cause fracture on a single application of load. — The term FATIGUE, ...

—A shear fracture occurs as the result of extensive slip on the active slip plane. —Shear fracture is promoted by shear stresses. —Single crystal of h.c.p. metals may slip on successive basal planes until finally the crystal separates by shear.

-   Brittle fracture is characterized by rapid rate of crack propa­gation with minimal energy absorption. —  A brittle fracture occurs by separation normal to tensil stress. —Brittle fractures have been observed in B.C.C. and H.C.P. metals but non F.C.C. metals: —In brittle fracture ...

Ductile fracture is characterized by appreciable plastic deformation prior to and during the propagation of crack. — Ductile fracture is always preceded by the localised deformation called necking (Fig. 55.3). Appreciable amount of gross deformation, thus is present at the fracture ...

It consists of two components (a)   Crack initiation. (b) Crack propagation

— Fracture is considered the end result of plastic deformation process. — Fracture is the separation of a body under stress into two or more parts. — Separation of the body (i.e., fracture) is caused either by physical or chemical forces. —  Fracture ...

Even though the number of failures of a particular component may be small, they are important because they may affect the manufacturer's reputation for reliability. In some cases, particularly when the failure results in personal injury or death, it will lead ...