Atomic resolution study of radiation-induced precipitation and solute segregation effects in a neutron-irradiated W-25 at. % Re alloy

Technical Report · Fri Jul 01 00:00:00 EDT 1983

OSTI ID:5994062

Herschitz, R; Seidman, D N

The phenomena of radiation-induced precipitation and solute segregation effects in a W-25 at.% Re alloy have been investigated using the atom-probe field-ion microscope. This alloy is supersaturated with respect to the solvus line of the primary ..beta..-solid solution; it is in the two-phase ..beta..-plus-sigma region. The specimens had been irradiated in the EBR-II to a fast-neutron fluence of approx. 4 x 10/sup 22/ neutrons cm/sup -2/ (E > 0.1 MeV) at 575, 625, and 675/sup 0/C. This fluence corresponds to 8.6 dpa and an average displacement rate, for the two-year irradiation time, of 1.4x10/sup -7/ dpa s/sup -1/. Results show significant alteration of the microstructure of this alloy as a result of neutron irradiation. Precipitates of the composition approx. WRe/sub 3/ (chi phase) have been detected. Coherent, semicoherent, and incoherent precipitates have been observed. Semicoherent and incoherent precipitates were associated with /sup 4/He atoms, i.e., heterogeneous precipitation has ocurred in this alloy. A very strong Re enrichment of grain boundaries has been observed, and no segregation to voids has occurred. Point-defect mechanisms for all of these observations are discussed.

• Research Organization: Cornell Univ., Ithaca, NY (USA). Materials Science Center
• DOE Contract Number: AC02-76ER03158
• OSTI ID: 5994062
• Report Number(s): DOE/ER/03158-109; ON: DE83015036
• Resource Relation: Other Information: Portions are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
RHENIUM ALLOYS
PHYSICAL RADIATION EFFECTS
TUNGSTEN BASE ALLOYS
FAST NEUTRONS
GRAIN BOUNDARIES
ION MICROSCOPY
MICROSTRUCTURE
POINT DEFECTS
SEGREGATION
ALLOYS
BARYONS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELEMENTARY PARTICLES
FERMIONS
HADRONS
MICROSCOPY
NEUTRONS
NUCLEONS
RADIATION EFFECTS
TUNGSTEN ALLOYS
360106* - Metals & Alloys- Radiation Effects