Preparation of some specific grain boundaries in aluminum for HREM studies by cold rolling and annealing

Journal Article · Mon Jan 01 04:00:00 EST 1990 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(90)90346-I· OSTI ID:6958817

Shamsuzzoha, M; Deymier, P A ^[1]

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1. Univ. of Arizona, Tucson (United States)

The preparation of bicrystals with an aim to study grain boundary structure by high resolution electron microscopy (HREM) requires a careful approach. Primary attention needs to be directed towards the orientations of the crystals forming a boundary so that atomic resolution images of the bicrystal can be achieved by HREM. Mader, Necker and Balluffi have reviewed the limitations of present day high resolution microscopes in resolving grain boundary structures. According to these authors, the resolution limit (information resolution limit = 0.14 nm) of such microscopes now allows most f.c.c. metallic crystals to reveal a projected point pattern along any of the <100>, <110>, <111> and <112> directions. Resolving a grain boundary structure requires simultaneous imaging of atomic columns in crystals on both sides of the boundary. For a very thin f.c.c. metallic bicrystal, a 1[degree] or less misorientation between neighboring crystals is required to achieve a simultaneous imaging of atomic columns across the interface. The [l brace]200[r brace], [l brace]220[r brace] and [l brace]111[r brace] projected line pattern of a f.c.c. metallic crystal can also be obtained with current microscopes. A misorientation of 1[degree] to 3[degree] between such planes of f.c.c metallic bicrystal can provide atomic plane resolution across the interface. Bicrystals meeting these criteria for HREM studies are usually prepared either by deposition of thin film on a suitable substrate or by solidification of a required orientation seeded bicrystal either by the Bridgeman technique or by the Czochralski technique. In the present work the authors investigated a relatively simple and inexpensive cross-rolling and annealing technique to obtain bicrystals of aluminum for HREM studies of grain boundary structures. A report is given of such preparation techniques for certain specific aluminum bicrystals, which were found suitable for HREM imaging.

• DOE Contract Number: FG02-87ER45285
• OSTI ID: 6958817
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 24; ISSN SCRMEX; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals &amp; Alloys-- Preparation &amp; Fabrication
360102 -- Metals &amp; Alloys-- Structure &amp; Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical &amp; Spectral Procedures
ALUMINIUM
ANNEALING
COLD WORKING
CRYSTAL STRUCTURE
DATA
DEPOSITION
ELECTRON MICROSCOPY
ELEMENTS
EXPERIMENTAL DATA
FABRICATION
FILMS
GRAIN BOUNDARIES
HEAT TREATMENTS
INFORMATION
MATERIALS WORKING
METALS
MICROSCOPY
MICROSTRUCTURE
NUMERICAL DATA
RESOLUTION
ROLLING
SAMPLE PREPARATION
SUBSTRATES
THIN FILMS