Dislocation Multiplication as a Controlling Factor of Work‐Hardening

Abstract
The dislocations responsible for defective structure in a KCl crystal are not only obstacles but also “sources” of multiplication for moving dislocations. It is shown that the process of multiplication of moving dislocations controls the work‐hardening of a crystal in the easy glide stage. The plastic deformation of a crystal is accompanied by repeated yield points arising from the discrete nature of dislocation multiplication. It is found that work‐softening (similar to stage III work‐hardening in f.c.c. metals) can occur in the plastic deformation of KCl crystals. In the discussion the concept about the controlling role of multiplication of moving dislocations is given as an alternative to the other point of view, which considers the work‐hardening process to be controlled by the resistance to dislocation motion.
Keywords