Research Information System
MATERIALS SCIENCE-POLAND, no.3, pp.919-926, 2009 (SCI-Expanded)
Structural characteristics and thermal behaviour of the conventionally solidified Al-Cu-Fe alloys with nominal compositions of Al(70)Cu(20)Fe(10), Al(65)Cu(20)Fe(15) and Al(63)Cu(25)Fe(12) were investigated by X-ray diffraction, scanning electron microscopy, and differential thermal analysis techniques. Results show that a single quasicrystalline phase forms in a conventionally solidified Al(65)Cu(20)Fe(15) alloy, being thermodynamically stable without phase transition up to the melting point. A cubic AlFe(Cu) solid solution, identified as beta phase, and a cubic AlCu(Fe) solid solution, identified as tau phase, were observed with quasicrystalline phase for Al(63)Cu(25)Fe(12) alloy. Conventional solidification of Al(70)Cu(20)Fe(10) alloy does not result in quasicrystalline phase formation. However, the formation of quasicrystalline phase in conventionally solidified Al(70)Cu(20)Fe(10) alloy was observed after additional annealing at elevated temperature. SEM micrographs for Al(70)Cu(20)Fe(10) and Al(63)Cu(25)Fe(12) alloys after annealing at 700 degrees C for 4 h revealed the formation of pentagonal dodecahedrons in the quasicrystalline phase, with an edge size of about 30 mu m.