SIMS study of deuterium trapping in ion implanted aluminum alloys

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efined Zr2A1 particles which precipitate during the quench following the preanneal and which are too small to be resolved in the optical microscope. 4. S u m m a r y . To summarize, structural refinement is an effective method for reducing the time for transforming two-phase Zr/Zr2A1 ingots into Zr3A1. The refinement results in increased nucleation rates, due to the increased surface-to-volume ratio of the Zr2AI particles, and in a shorter growth period due to the smaller diffusion distances involved. The experiments were performed at the Chalk River Nuclear Laboratories of the Atomic Energy of Canada Ltd., while the author was associated with the laboratories. The technical assistance of D. B. Graham, V. Ling and D. H. McColl is gratefully acknowledged.

I. E. M. Schulson and D. B. G r a h a m : Acta Metall., 1976, vol. 24, p. 615. 2. E. M. Schulson and D. B. G r a h a m : J. Nucl. Mater., 1975, vol. 57, p. 358. 3. B. J. Shaw: Acta Metall., 1967, vol. 15, p. 1169. 4. H. E. Cline and D. Lee: Acta Metall., 1970, vol. 18, p. 315. 5. E. M. Schulson and J. A. Roy: Met. Trans. A , 1977, vol. 8A, p. 377. 6. I.. M. Howe, M. Rainville, and E. M. Schulson: J. Nucl. Mater., 1974, vol. 50, p. 139.

SIMS Study of Deuterium Trapping in Ion Implanted Aluminum Alloys A. K. Z U R E K , H. L. MARCUS, J. N. CECIL, A N D R. POWERS The aim of this communication is to describe a deuterium-in-aluminum trapping inversion experiment. Deuterium ions, deposited at a sharply-defined depth by cyclotron irradiation, undergo diffusion and reversible trapping. This leads to a gradual redistribution of the deuterium atoms within the metal and their slow evaporation from its s u r f a c e - - a n inverse of the usual adsorption and transport mechanism used to describe deuterium originating at the surface. It has been shown that humid air and water vapor increase crack propagation rate in aluminum alloys but dry hydrogen has no effect. ~ 8 At room temperatures, diffusivity of hydrogen in metals is extremely high and exceeds that of heavy interstitials like oxygen and nitrogen by 15 to 20 orders of magnitude. 9 Penetration of hydrogen during fatigue crack growth was shown to be deeper than the predicted depth for simple diffusion using the sweep-an concept. ~~ The time scale of A. K. Z U R E K and H. L. M A R C U S are Graduate Student and Professor, Materials Science and Engineering, Department of Mechanical Engineering, the University of Texas at Austin, Austin, TX 78712. J. N. C E C I L and R. P O W E R S are Chief Scientist and Senior Engineer, Accelerators, Inc., Austin, T X 78760. Manuscript submitted April 7, 1980.

ISSN 0360-2133/80/1111-1920500.75/0 9 1980 A M E R I C A N SOCIETY FOR M E T A L S A N D M E T A L L U R G I C A L T R A N S A C T I O N S A T H E M E T A L L U R G I C A L SOCIETY OF A I M E

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