Polygonization in high-purity rolled (001)[110] tungsten single crystals

Electron microscopy is used to study changes in the dislocation structure of high-purity rolled (001)110] tungsten single crystals during short-term high-temperature annealings. The effects of the annealing temperature and time on the formation of low-angle boundaries are investigated. Local defects, which are similar to those detected earlier upon annealing in the structure of molybdenum single-crystal ribbons, are found to form and dissociate upon annealing. These defects are concluded to have a dislocation nature.