High resolution detection of solute segregation to the cores of dislocations in grain boundaries. [Fe--0. 8 at. % Au]

Technical Report · Mon Feb 29 23:00:00 EST 1988

OSTI ID:5002684

Michael, J R; Lin, C H; Sass, S L

Thin film Fe--0.8 at. % Au bicrystals, /approximately/60 nm thick, containing (001) twist boundaries were prepared. The average compositon of the bicrystal was determined by Rutherford backscattering spectroscopy (RBS), which also showed that the Au was nonuniformly distributed along the direction normal to the interface, with a large amount concentrated at the (001) twist boundary. This observation constitutes direct evidence that the Au is segregated to the vicinity of the grain boundary. The Au distribution within the plane of the interface was analyzed in a Vacuum Generators HB-501 scanning transmission electron microscope (STEM) equipped with a field emission electron source and a Link Analytical windowless x-ray detector. The boundary plane was oriented perpendicular to the electron beam. Digital line scans were performed across the dislocation network. Au segregates extensively to the cores of the <100>-type dislocations in small angle (001) twist boundaries in Fe--Au alloys. Our observations demonstrate that the <110> network is favored in pure Fe, which leads to the suggestion that the dislocation core energy plays an important role in determining the stable boundary structure.

• Research Organization: Bethlehem Steel Corp., PA (USA). Homer Research Lab.; Cornell Univ., Ithaca, NY (USA). Dept. of Materials Science and Engineering
• DOE Contract Number: FG02-85ER45211
• OSTI ID: 5002684
• Report Number(s): DOE/ER/45211-8; MSC-6391; ON: DE88009168
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals &amp; Alloys-- Structure &amp; Phase Studies
ALLOYS
BICRYSTALS
BURGERS VECTOR
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DISLOCATIONS
ELECTRON MICROSCOPY
ELEMENTS
FILMS
GOLD
GOLD ALLOYS
GRAIN BOUNDARIES
IMAGES
IRON ALLOYS
LINE DEFECTS
METALS
MICROSCOPY
MICROSTRUCTURE
POLYCRYSTALS
SEGREGATION
THIN FILMS
TRANSITION ELEMENTS