The dislocation sub-structures of polycrystalline -phase material of commercial purity was studied after tensile deformation, at temperatures of between 4.2, 77 and 293K, by means of transmission electron microscopy. The stability of elements of the sub-structure was studied with respect to changes in the deformation temperature. It was found that reorientation bands, which arose from pre-deformation at 293K, gradually degraded during subsequent deformation at 4.2 and 77K and were subject to fragmentation by low-temperature twins (for which they were not insurmountable obstacles). If the temperature was changed in the reverse sequence, the formation of reorientation bands was impeded or even suppressed, and low-temperature twins became insurmountable obstacles to reorientation bands.

A.R.Smirnov, V.A.Moskalenko: Acta Metallurgica et Materialia, 1994, 42[8], 2603-7