Dislocation structure in molybdenum single crystals after deformation at 293deg and 400degK

Abstract Molybdenum single crystals, oriented for slip on (101)[111] were deformed in tension at 293° and 400°K. Thin foils parallel to the primary and conjugate slip planes were examined under the electron microscope. The development of dislocation structures with strain, dislocation densities, Burgers vectors and dislocation walls were studied. The changes in the dislocation structure are discussed in terms of the temperature- and stress-dependent cross slip of screw dislocations. The multiple slip at the beginning of deformation and single slip in the region of easy glide are explained on the assumption that surface sources are active in stage 0 and internal sources in stage I.