Steady-State Creep of Crystals

An expression for the steady‐state creep rate of crystals is derived for the case where dislocation climb is not rate controlling. Two rate‐controlling processes are considered. In the first the dislocations are considered to move in a viscous manner, their velocity of motion being proportional to the force exerted on them. The second mechanism makes use of the Peierls stress. The Peierls stress mechanism can be used to explain the results of Gilman on creep by prismatic glide in high‐purity zinc. At low stresses the analysis for both processes leads to a power law stress dependence for the creep rate. The value of the exponent of the stress is approximately equal to three.