DISLOCATIONS IN DEFORMED AND ANNEALED NIOBIUM SINGLE CRYSTALS

Journal Article · Thu Aug 01 04:00:00 EDT 1963 · Acta Met.

DOI:https://doi.org/10.1016/0001-6160(63)90054-3· OSTI ID:4685445

Stiegler, J O; Dubose, C K.H.; Reed, Sr, R E; McHargue, C J

Dislocation configurations in deformed and annealed niobium single crystals were observed by transmission electron microscopy. Grown-in dislocations were observed to act as sinks for interstitials; this action retarded climb during annealing and possibly made the dislocations immobile during deformation. Three dimensional walls of dislocation tangles formed early in the deformation process and surrounded cells relatively free of dislocations. During the initial annealing stages, dislocations in the cell walls rearranged themselves to form well-defined small-angle boundaries between adjacent cells. After 1 hr at 700 deg C a few recrystallized grains, rotated 20-30 deg about STA111! from the surrounding cell structure were observed. Nucleation and growth of these particular recrystallized grains probably occurred because of the partiai coincidence of lattice sites between them and the unrecrystallized material. Growth slowed down appreciably as the grains grew into material that did not bear the special orientation relationship with the recrystallized grain. Regions in which the grains were not nucleated recrystallized without a change in orientation by the gradual sweeping out of dislocations. (auth)

• Research Organization: Oak Ridge National Lab., Tenn.
• NSA Number: NSA-17-029336
• OSTI ID: 4685445
• Journal Information: Acta Met., Journal Name: Acta Met. Vol. Vol: 11
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ANNEALING
CONFIGURATION
DEFECTS
DEFORMATION
DISLOCATIONS
ELECTRON MICROSCOPY
EXPANSION
GRAIN BOUNDARIES
GRAIN SIZE
HIGH TEMPERATURE
LATTICES
METALS, CERAMICS, AND OTHER MATERIALS
MONOCRYSTALS
NIOBIUM
NUCLEATE BOILING
RECRYSTALLIZATION