Hardening by ordered coherent precipitates related to the statistical theory

Abstract

The hardening of a metal by a dispersion of spherical ordered and coherent precipitates is analysed on the basis of a previous statistical theory, which described the motion of a dislocation through a random array of obstacles in its slip plane. By using the flow-stress–obstacle strength relationship, it is found that small precipitates are cut by the dislocations, whereas large precipitates are by-passed. At the limit between the two processes, the hardening goes through a maximum, of which certain physical parameters can be deduced.