Effect of microstructure on helium bubble growth in irradiated nickel

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6909992

Sattler, M L

Thin nickel films were irradiated with 80 keV helium ions at varying doses and varying temperatures in order to obtain a variety of final microstructures. The growth of bubbles was examined during in-situ irradiations at 950/sup 0/C where migration and coalescence events were observed for bubbles as large as 60 nm. Further direct observations of bubble growth were made during annealing of the irradiated specimens. For sample with no visible bubbles before annealing, the heating to 0.51 T/sub M/ produced bubbles that increased in diameter with annealing time to the power n. For bubbles in the grain interior, n approx. 1, and on the grain boundaries, n approx. 0.6. Since no migration and coalescence or ripening theories predict this behavior, a theory described by transient diffusion to spherical sinks was developed to discuss the behavior. This theory predicts that n = 1 for bubbles growing in the grain interior and n = 0.5 for bubbles on the grain boundary. In other annealing of irradiated samples containing large bubble populations, the growth of large bubbles and shrinking of small bubbles was observed at a temperature equal to 0.54 T/sub M/. The theory of Ostwald ripening properly described this type of bubble growth. Mass spectrometer measurements of He content in the irradiated specimens showed a greater He retention in the Ni films that contained a significant bubble population than those with no visible bubbles.

• Research Organization: Virginia Univ., Charlottesville (USA)
• OSTI ID: 6909992
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360106* -- Metals & Alloys-- Radiation Effects
BEAMS
BUBBLE GROWTH
CHARGED PARTICLES
CRYSTAL STRUCTURE
ELEMENTS
ENERGY RANGE
FILMS
FLUIDS
GASES
HELIUM
HELIUM IONS
ION BEAMS
IONS
KEV RANGE
KEV RANGE 10-100
METALS
MICROSTRUCTURE
NICKEL
NONMETALS
PHYSICAL RADIATION EFFECTS
RADIATION EFFECTS
RARE GASES
THIN FILMS
TRANSITION ELEMENTS