A transmission electron microscopic study of icosahedral twins. 1: Rapidly solidified Al-Mn-Fe alloys

Journal Article · Fri Sep 01 00:00:00 EDT 1995 · Acta Metallurgica et Materialia

DOI:https://doi.org/10.1016/0956-7151(95)00024-P· OSTI ID:105992

Singh, A; Ranganathan, S ^[1]

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1. Indian Institute of Science, Bangalore (India). Centre for Advanced Study

Dendrites of the icosahedral quasicrystalline phase in an aluminum matrix were formed on rapid solidification of an Al{sub 90}Mn{sub 5}Fe{sub 5} alloy. A large number of these particles was found to be twinned with one of the five-fold symmetry axes as the twin axis, as established by careful tilting experiments in the transmission electron microscope. The twin relationship can be expressed in 60 different ways by a rotation around seven different axes of the icosahedral and utilizing 12 different angles. In the alloys of composition Al{sub 86}Mn{sub 7}Fe{sub 7} and Al{sub 80}Mn{sub 10}Fe{sub 10} an icosahedral phase, Al{sub 3}Fe and {alpha}-Al formed at wheel surface velocities about 23.5 m/s. The icosahedral phase in these alloys is not twinned. At 12 m/s wheel velocity only Al{sub 3}Fe and {alpha}-Al formed. The relationship of the icosahedral twin to the decagonal phase has been brought out.

• OSTI ID: 105992
• Journal Information: Acta Metallurgica et Materialia, Journal Name: Acta Metallurgica et Materialia Journal Issue: 9 Vol. 43; ISSN 0956-7151; ISSN AMATEB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM BASE ALLOYS
CRYSTAL STRUCTURE
DENDRITES
INTERMETALLIC COMPOUNDS
IRON ALLOYS
MANGANESE ALLOYS
MORPHOLOGY
PHASE STUDIES
SOLIDIFICATION
TWINNING