Stress Relaxation in Single-Crystal Iron Deformed in Tension.

Relaxation of high purity single crystals of iron was investigated at 77 to 296 K. It was found that the phenomenon of relaxation can be expressed by a logarithmic law or a power function. For all specimens tested a definite relation seemed to exist between the activation volume and the thermal component of the stress. At below 192 K, the slip characteristics (especially the activation volume) did not depend on either purity or orientation of the specimen. Near room temperature, the results seemed to depend on purity. Explanations are suggested.