Microstructural analysis by high-voltage electron diffraction of severely drawn iron wires

摘要: Transverse sections of Fe-0.007 wt pct C wires drawn to true strains up In(D o/D)2= 6 were examined by transmission electron microscopy at 800 kV, using bright-field and selected-area diffraction. The size the area selected (0.1 μm) enabled single-crystal diffraction patterns be obtained from individual cells in substructure. Because characteristic (110) bec wire texture, nearly all (110), so it was possible describe completely relative misorientations groups 50 contiguous with an accuracy about 0.5 deg. In this way, maps showing size, shape, crystallographic orientation, grouping cells. These illustrate development cellular substructure large deformations as evolves many, slightly misoriented crystallites initially grains (at unity less) a much smaller number strongly misoriented, fibrous subgrains each severely elongated grain above 4). trend is toward pure tilt boundaries very misorientation one cell per highest strains. It necessary consider both slip distance (which probably greater than average size) forest-dislocation density (represented walls cut glide dislocations) order characterize microstructure Jflow-stress relationship.