PLASTICITY AND CREEP IN SINGLE CRYSTALS OF ZIRCONIUM CARBIDE

High‐temperature deformation in ZrC single crystals was studied. Seeded crystals were grown by a direct rf‐coupling floating‐zone process. Yield stresses were measured from 1080° to 2000°C as a function of stress axis orientation. The Burgers vector was shown to be parallel to the 〈110〉 axes by transmission electron microscopy. Slip was observed on {100}, {110}, or {111} planes, depending on the orientation of the stress axis; it always occurred on the most favorably oriented slip system. The dependence of steady‐state creep rate on the applied stress indicated that recovery occurred by a dislocation climb mechanism. Examination of the dislocation structure in deformed crystals by transmission electron microscopy supported this conclusion. Copyright © 1969, Wiley Blackwell. All rights reserved