The plastic bending of NaCl

Abstract

Four-point bending tests have been carried out on cleaved and annealed NaCl single crystals. The stress distribution in the bent crystals has been determined photoelastically and an etch-pit technique was used to study the dislocation distribution. The observed dislocation density is greater than the density of dislocations of one sign needed to accommodate the bending produced, indicating that dislocations of both signs are present. A simple dislocation model is used to discuss the results.