Dislocation channel formation process in V-Cr-Ti alloys irradiated below 300 deg. C

Atomic force microscopy was applied to study the slip band evolution of neutron-irradiated V-Cr-Ti alloys deformed in a tensile test. Quantitative data were obtained on the changes of the surface topography of dislocation channels and on the kinetics of dislocation channel growth up to the ultimate tensile stress. As stress approached the ultimate tensile strength, the slip bands nucleated and propagated across the specimens. As the stress increased, the interval spacing between slip bands decreased and became constant. On the other hand, the slip step height continued to increase, and indicated that the growth of individual dislocation channels occurred continuously. The conjugated and multi-slip bands in a grain were seldom observed. The evolution of dislocation channels may induce the significant loss of ductility after the UTS in V-Cr-Ti alloys