Experimental evidence for positron trapping at dislocations in Ni/sub 3/Al alloys

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6825831

Usmar, S G; Lynn, K G

Cold worked Ni/sub 3/Al alloys were studied using positron lifetime spectroscopy. The isochronal annealing curves of Ni/sub 76/Al/sub 24/ + 0 and 500 at. ppM B were measured. In pure Ni/sub 76/Al/sub 24/ three annealing stages were identified while in the boron doped alloy only two were identified. Vacancy annealing (stage III) was found to start at /approximately/250/degree/C in reasonable agreement with previously published data for both alloys. The high temperature annealing stage in boron doped Ni/sub 76/Al/sub 24/ starts between 750 and 800/degree/C and is complete at 1000/degree/C. This stage was attributed to migration of dislocations to various sinks. In pure Ni/sub 76/Al/sub 24/ the intermediate and high temperature annealing stages occur at 750 to 800 and 1050/degree/C, respectively. These stages were attributed to the migration of dislocations (750--800/degree/C) and recrystallization (/approximately/1050/degree/C). The nature of the dislocation trap will be discussed.

• Research Organization: Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6825831
• Report Number(s): BNL-41322; CONF-8808122-13; ON: DE89004520
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
656002* -- Condensed Matter Physics-- General Techniques in Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
ANNIHILATION
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BASIC INTERACTIONS
COLD WORKING
DOPED MATERIALS
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
FABRICATION
FERMIONS
INTERACTIONS
LEPTONS
LIFETIME
LINE WIDTHS
MATERIALS
MATERIALS WORKING
NICKEL ALLOYS
POSITRONS
TEMPERATURE DEPENDENCE
TRAPPING