CXI. Brittle fracture and yielding

Abstract

The stresses round a piled-up group of dislocations may either initiate a crack or operate a Frank-Read source by pulling it from its locking impurities; the latter is related to the propagation of a Lüders band. This interpretation leads to results in accord with experiment. The model gives a sharp transition from brittle to ductile behaviour as the temperature is increased.