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

Singh, Alok and Ranganathan, S (1995) A transmission electron microscopic study of icosahedral twins- II. A rapidly solidified Al-Cu-Fe alloy. In: Acta Metallurgica et Materialia, 43 (9). pp. 3553-3562.

 PDF A_TRANSMISSION-58.pdf Restricted to Registered users only Download (4078Kb) | Request a copy

## Abstract

Twinning of the ordered icosahedral quasicrystal has been studied by transmission electron microscopy in a melt-spun $Al_{75} Cu_{12.5} Fe_{12.5}$ alloy. Dendrites of about $10 \mu m$ 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 $1 \mu m$ size are twin related through a common five-fold axis to several neighbouring 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 $Al_3Fe$ phase in ten-fold multiply twinned form were also observed.

Item Type: Journal Article Copyright of this article belongs to Elsevier. Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) 18 Sep 2006 19 Sep 2010 04:31 http://eprints.iisc.ernet.in/id/eprint/8629