Two-subgrain single quasicrystals Al-Cu-Co alloy growth and characterisation

Two-subgrain single quasicrystals with subgrain boundaries parallel to the direction of solidification were obtained by the modification of Bridgman method. with asymmetric heat abstraction. One of the subgrains of single quasicrystals was formed through the peritectic reaction of the Al(Cu,Co) phase. The other subgrain solidified directly from the melted phase. Two different types of band structures of single quasicrystals were determined by X-ray topography and metallography methods. The orientation of these structures in relation to the ten-fold symmetry axis of single quasicrystal and the solidification front was investigated. The formation mechanism of both kinds of structure were suggested. (C) 2002 Elsevier Science B.V. All rights reserved.