Determination of grain boundary volume expansion by HREM

Conference · Tue Mar 01 04:00:00 EST 1994

OSTI ID:10144612

Buckett, M I; Merkle, K L

High resolution electron microscopy (HREM) has provided invaluable insight into the structure of grain boundaries at the atomistic level. Quantitative HREM methods are now in development which, combined with atomistic simulations, can provide further insight into grain boundary structure-energy correlations. For example, the volume expansion (or excess free volume, {delta}), a thermodynamic parameter directly related to the grain boundary energy, is represented by the normal component of the rigid body translation. Although its magnitude is small, it can be determined experimentally using statistical techniques which locate and fit the peak and valley positions in an experimental HREM image - i.e., a direct measurement of the lattice fringe displacements is made. We have modified the lattice fringe displacement technique such that a measurement accuracy of better than {plus_minus}0.002a{sub o} can be achieved. Precise knowledge of the position and intensity of the image contrast and a detailed understanding of the sources of error are required. This paper provides a detailed description of the lattice fringe displacement technique as well as an analysis of the sources of error in the measurement.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 10144612
• Report Number(s): ANL/MSD/CP--82465; CONF-940275--2; ON: DE94010452
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102
440800
47 OTHER INSTRUMENTATION
ELECTRON MICROSCOPY
ERRORS
EXPANSION
GOLD
GRAIN BOUNDARIES
MEASURING METHODS
MISCELLANEOUS INSTRUMENTATION
STRUCTURE AND PHASE STUDIES
THERMODYNAMIC PROPERTIES
TWINNING
VOLUME