Slip planes and asymmetric slip in fatigue of iron single crystals

Abstract

Abstract Slip planes in iron single crystals are identified and the relative critical resolved shear stresses for slip on those planes are estimated from the results of torsional fatigue experiments. The torsional mode of fatigue is uniquely suited for these purposes because, generally, two different slip systems operate in a given region of maximum resolved shear stress. One slip system can be identified with one sense of shear and the other slip system with the opposite sense of shear. This effect is due to asymmetry of slip on certain planes. Slip is found to occur on {110}, {112} and {123} planes and to be asymmetric on {112} and {123} planes. The relative critical resolved shear stresses are ranked from tests on a number of different orientations.