Tóm tắt
Phenomenological equations between dislocation velocity, effective shear stress, temperature, and pressure are presented. It is suggested that the term "activation volume" be properly assigned to the pressure dependence of dislocation velocity. Indirect methods of determining velocity–stress relations are reviewed, and a new method is introduced using the stress–time data in stress relaxation. Some results are reported for high-purity iron, LiF, and NaCl crystals. Phenomenological relations near absolute zero are examined in the light of the third law of thermodynamics. These relations are illustrated with the deformation behavior of potassium at liquid helium temperatures.
