The crystallization and growth of AlB{sub 2} single crystal flakes in aluminum
- Department of Materials Science and Engineering, University of Illinois, Urbana, Illinois 61801 (United States)
- Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States)
An {ital in situ} high temperature heat treatment was used to investigate the crystallization and growth behavior of AlB{sub 2} flakes in aluminum. Aluminum samples containing 1.8{percent} boron were heated above the liquidus and then rapidly cooled through the Al{sub (L)}+AlB{sub 12} region to avoid the formation of AlB{sub 12} crystals. Subsequently, a homogeneous distribution of high aspect ratio AlB{sub 2} flakes crystallized upon holding below the peritectic transition temperature. Growth rate in the (a) and (c) dimensions increased during elevated hold temperatures below the peritectic transition temperature. Surprisingly, faster cooling rates from above the liquidus to room temperature resulted in thinner, wider flakes. Similar to graphite this phenomenon is believed to result from a need to accommodate a changing misfit strain energy between the solidifying aluminum and the growing AlB{sub 2} flakes. {copyright} {ital 1998 Materials Research Society.}
- OSTI ID:
- 289222
- Journal Information:
- Journal of Materials Research, Vol. 13, Issue 12; Other Information: PBD: Dec 1998
- Country of Publication:
- United States
- Language:
- English
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