Plastic deformation of potassium chloride single crystals due to 5-MHz ultrasonic waves

Long-range movement of Frank-Read source generated dislocation loops, produced by intense longitudinal 5-MHz ultrasonic waves, was observed in potassium chloride single crystals by stress-optical and etching techniques. Dislocation multiplication of individual dislocation sources along particular slip planes was noted. Plastic deformation of KCl crystals by ultrasonic standing waves is explained by the movement and multiplication of dislocations in the antinodal planes in accordance with the models proposed by Frank and Read and Koehler and Orowan. Concentrations of edge dislocations were observed in the nodal planes of the ultrasonic wave in accordance with the low dislocation mobility at a low shear-stress level.