A transmission electron microscopic study of icosahedral twins. 2: A rapidly solidified Al-Cu-Fe alloy

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

DOI:https://doi.org/10.1016/0956-7151(95)00025-Q· OSTI ID:105993

Singh, A; Ranganathan, S ^[1]

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

Twinning of the ordered icosahedral quasicrystals has been studied by transmission electron microscopy in a melt-spun Al{sub 75}Cu{sub 12.5}Fe{sub 12.5} alloy. Dendrites of about 10 {micro}m of the icosahedral phase, formed near the wheel side of the melt spun ribbons, have been observed to twin extensively so that a multiple twinning of the grains is observed. Regions of about 1 {micro}m size are twin related through a common five-fold axis to several neighboring regions. The possibility of different orientations of the twins formed by repeated twinning is infinite. Thus the multiple twinning gives rise to a random symmetry for the whole grain. Depending on the undercooling achieved across the melt-spun ribbons, several related phases like the decagonal quasicrystal and crystalline monoclinic Al{sub 3}Fe phase in ten-fold multiply twinned form were also observed.

• OSTI ID: 105993
• 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
COPPER ALLOYS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DENDRITES
GRAIN SIZE
INTERMETALLIC COMPOUNDS
IRON ALLOYS
ORIENTATION
PHASE STUDIES
TWINNING