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 [Formula: see text] by four-point bending at 77 °K. On the compression side of the specimens with orientations [Formula: see text] the slip planes were found to be very close to those with maximum resolved shear stress. On the compression side of the specimens with [Formula: see text] and on the tension side of specimens with [Formula: see text] (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.