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Electron Microscopic Investigation of the Dislocation Structure in Molybdenum Single Crystals Deformed in Tension at 293 and 493 °K
Author(s) -
Luft A.,
Kaun L.
Publication year - 1970
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.19700370229
Subject(s) - substructure , materials science , dislocation , crystallography , transmission electron microscopy , condensed matter physics , molybdenum , work hardening , hardening (computing) , dipole , deformation (meteorology) , tension (geology) , frank read source , dislocation creep , ultimate tensile strength , composite material , metallurgy , microstructure , chemistry , nanotechnology , physics , structural engineering , organic chemistry , layer (electronics) , engineering
The dislocation structure of high purity molybdenum single crystals after weak tensile deformation at 293 and 493 °K is studied by transmission electron microscopy. The transition from parabolic stress—strain behaviour to three‐stage hardening which occurs between the considered temperatures is associated with a basic change in the deformation substructure. Crystals deformed at 293 °K contain a uniform distribution of long primary and secondary screw dislocations. On the contrary, the dislocation structure in stage I at 493 °K consists mainly of isolated clusters of primary edge dipoles. It is concluded that the effect of temperature on the mobility of screw dislocations is responsible for the change observed both in work‐hardening characteristics and related dislocation structures.