Slip Planes in fe - 3% si Single Crystals Deformed at 77 °K

Macroscopic slip planes were determined on specimens of different orientations, cut from a single crystal of Fe – 3% Si alloy after slow deformation by four-point bending at 77 °K. On the compression side of the specimens with orientations the slip planes were found to be very close to those with maximum resolved shear stress. On the compression side of the specimens with and on the tension side of specimens with (except the specimens with χ = ±30°) either crystallographic slip along {110} planes or large deviations of slip planes from maximum resolved shear stress planes to {110} planes were observed. The ψ(χ) curves obtained at 77 °K are compared with those obtained similarly at room temperature. The ψ(χ) curves for 77 °K cannot be explained microscopically on the basis of the composite slip on {110} and {112} planes if only the effect of the slip sense is assumed.