The Effects of Short‐Range Order and Long‐Range Order on the Equilibrium Configuration of Superdislocations in FeCo : 2 at% V — Consequences on Flow Stress

The variations in flow stress of FeCo : 2 at% V as a function of test or quench temperature exhibit a maximum near the critical temperature for ordering, Tc. Transmission microscope study of thin foils reveals the existence of paired dislocations not only at temperatures below Tc but also at temperatures above Tc where only short‐range order exists; calculations of their equilibrium spacing using the quasi‐chemical theory [6] are in agreement with experimental results. The peak in flow stress may be explained assuming that for high values of S (S is the long‐range order parameter) the dislocation sources are constituted by paired dislocations which keep parallel configurations when operating, and that for low values of S (or S = 0) sources are constituted by single dislocations or by paired dislocations with only one of them operating.