Approximants in annealed IQC(Icosahedral Quasicrystal)-DQC(Decagonal Quasicrystal) pseudo-binary alloys
(1. State Key Laboratory for Materials Modification, Department of Materials Engineering, Dalian University of Technology, Dalian 116024, China;
2. LSG2M, CNRS-UMR7584, Ecole des Mines,
Parc de Saurupt, 54042 Nancy Cedex, France;
3. Institute of Material & Technology,
Dalian Maritime University, Dalian 116024, China)
2. LSG2M, CNRS-UMR7584, Ecole des Mines,
Parc de Saurupt, 54042 Nancy Cedex, France;
3. Institute of Material & Technology,
Dalian Maritime University, Dalian 116024, China)
Abstract: The structure and microstructure of constituent phases in annealed IQC100-xDQCx alloys, made from mixtures of Al62Cu25.5Fe12.5 icosahedral quasicrystal (IQC) and Al70Co15Ni15 decagonal quasicrystal (DQC), were studied by X-ray diffractometry(XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDAX). These constituent phases are mostly approximants: λ, β and τ3. In addition, an Al-Cu-Co DQC phase is observed in IQC80DQC20 alloy. The nature of these approximants and their relationship with the quasicrystals(QCs) are discussed; and the evolution of these phases is interpreted by the shifting of their e/a-constant lines in the Al-(Cu, Ni)-(Fe, Co) pseudo-ternary phase diagrams.
Key words: quasicrystals; approximants; phase diagram; e/a-constant line