NATURE OF OBSTACLES TO DISLOCATION MOTION IN CU AND CU-SI SOLID SOLUTIONS

The nature of obstacles to dislocation motion in copper single crystals has been studied by determining their effective retarding force–distance relationship as a function of solute content (up to 7 a/o silicon) and state of deformation. The obstacle energy is found to be 0·67 ev ± 0·06 ev, independent of solute content and state of deformation. While the rate-controlling barrier is independent of solute content and state of deformation, the athermal portion of the internal retarding force is observed to increase with state of deformation but to decrease markedly with increasing solute content. The results are consistent with a dislocation intersection mechanism which is discussed in detail. © 1968 Taylor & Francis Group, LLC.