Tracer diffusion in pure and boron-doped Ni/sub 3/Al

Journal Article · Sun May 01 04:00:00 EDT 1988 · Acta Metall.; (United States)

DOI:https://doi.org/10.1016/0001-6160(88)90279-9· OSTI ID:6359219

Hoshino, K; Rothman, S J; Averback, R S

Diffusion of /sup 63/Ni has been measured in pure and boron-doped polycrystalline Ni/sub 3/Al intermetallic compounds as a function of temperature (692-1352/sup 0/C), Al concentration (24-26 at.%Al), and boron content (0-500 wt ppm). Volume and grain-boundary diffusion of /sup 60/Co and /sup 68/Ge have also been measured in pure Ni/sub 3/Al. Both conventional grinding and ion beam sputtering techniques have been used for the determination of the concentration profiles. The diffusivity of Ni,D*/sub Ni/ is independent of Al content above 1000/sup 0/C, indicating that antisite defects are prevailing on both sides of stoichiometry. However, D*/sub Ni/ shows a minimum at the stoichiometric composition below 1000/sup 0/C, and this trend becomes clearer with decreasing temperature. The diffusivities of /sup 60/Co and /sup 68/Ge are also independent of Al concentration in the temperature range between 880 and 1200/sup 0/C, but their grain-boundary diffusion depends on Al concentration. The addition of boron linearly increases D*/sub Ni/ above 1000/sup 0/C, but at lower temperatures, D*/sub Ni/ in off-stoichiometric compositions decreases to the value for stoichiometric Ni/sub 3/Al on the addition of 100 wt ppm boron, and then increases as above with the further additions of boron to -- 500 wt ppm. The present diffusion data suggest that a small concentration of vacancies, independent of temperature, is present on both sides of, and at, stoichiometry at low temperature.

• Research Organization: Mitsui Mining and Smelting, Central Research Lab., Saitama (JP)
• OSTI ID: 6359219
• Journal Information: Acta Metall.; (United States), Journal Name: Acta Metall.; (United States) Vol. 36:5; ISSN AMETA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
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Cermets
& Refractories-- Preparation & Fabrication
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
656003 -- Condensed Matter Physics-- Interactions between Beams & Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
ALUMINIUM
ATOM TRANSPORT
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BORON ADDITIONS
BORON ALLOYS
CHEMISTRY
COBALT 60
COBALT ISOTOPES
COMMINUTION
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DAYS LIVING RADIOISOTOPES
DIFFUSION
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
GERMANIUM 68
GERMANIUM ISOTOPES
GRAIN BOUNDARIES
GRINDING
HIGH TEMPERATURE
HOT ATOM CHEMISTRY
INTERMEDIATE MASS NUCLEI
INTERMETALLIC COMPOUNDS
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LOW TEMPERATURE
MACHINING
METALLURGICAL EFFECTS
METALS
MICROSTRUCTURE
MINUTES LIVING RADIOISOTOPES
NEUTRAL-PARTICLE TRANSPORT
NICKEL 63
NICKEL ISOTOPES
NUCLEI
ODD-ODD NUCLEI
POINT DEFECTS
POLYCRYSTALS
RADIATION TRANSPORT
RADIOCHEMISTRY
RADIOISOTOPES
SPUTTERING
STOICHIOMETRY
TECHNOLOGY ASSESSMENT
TEMPERATURE DEPENDENCE
VACANCIES
YEARS LIVING RADIOISOTOPES