Frank loop unfaulting mechanism in fcc metals during neutron irradiation
The unfaulting mechanism whereby sessile Frank dislocation loops evolve into a complex tangle of glissile dislocations during irradiation of face centered cubic metals is not well understood. It is presumed that such loops grow by absorption of point defects until interactions develop which provide sufficient impetus for nucleation of an unfaulting event. The loops then become glissile, interact and form a dislocation network. An alternate mechanism which has been observed to occur in an austenitic precipitation-strengthened commercial alloy irradiated in the EBR-II fast reactor. The mechanism requires an interaction between the sessile a/3 <111> Frank loop and a moving glissile a/2 <110> perfect dislocation. An unfaulting a/6 <112> dislocation is created which, as it moves, eliminates the Frank loop and leaves only a perfect dislocation with the original a/2 <110> Burgers vector. This process is demonstrated. This alternate mechanism can have significant impact on the development of the dislocation microstructure in a metal undergoing irradiation creep. This impact will be discussed in relation to relevant irradiation creep models.
- Research Organization:
- Hanford Engineering Development Lab., Richland, WA (USA)
- DOE Contract Number:
- AC14-76FF02170
- OSTI ID:
- 5311531
- Report Number(s):
- HEDL-SA-2078; CONF-800696-1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360106* -- Metals & Alloys-- Radiation Effects
ALLOYS
BARYONS
BORON ADDITIONS
BORON ALLOYS
CARBON ADDITIONS
CHROMIUM ALLOYS
CREEP
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DISLOCATIONS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
IRON ALLOYS
LINE DEFECTS
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
MOLYBDENUM ALLOYS
NEUTRONS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIMONIC
NIMONIC PE16
NUCLEATION
NUCLEONS
PHYSICAL RADIATION EFFECTS
POINT DEFECTS
RADIATION EFFECTS
TITANIUM ALLOYS
ZIRCONIUM ADDITIONS
ZIRCONIUM ALLOYS