| Quasicrystals (QCs) consist mainly of icosahedral clusters. The local atomic configurations in amorphous metallic alloys comprise mainly close packed atomic configurations. Icosahedron is also one of the thermally stable clusters in these configurations. Recently, QC phases were found as the primary crystalline phase in many bulk amorphous alloys. This confirms the existence of close relationships between the local atomic configurations in the amorphous alloys and the icosahedral local order in the QC phases.The main idea of this study is to take advantage of their structural similarities, using QCs as alloying components to provide icosahedral clusters into the alloy system. In addition, Zr with large atomic radius is introduced to increase the amount of close packed polyhedra in the alloy. Through these alloying routes, the purpose is to find amorphous alloys having high glass forming abilities and through studying the structure evolution of the constituent phases in the alloys from QC system to amorphous system, try to investigate the probable correlations between them.In order to implement this idea, two pseudo-ternary alloy systems have been constructed: namely Icosahedral Quasicrystal (IQC)-Decagonal Quasicrystal (DQC)-Zr and IQC-Ni-Zr.In the first alloy system, at first, IQC-Al62Cu25.5Fe12.5 was mixed with DQC-Al70Co15Ni15 in different proportions. As a result, IQC100-xDQCx (x in wt.%) alloys were prepared. X-ray diffraction analysis proves that, in addition to the two initial QCs, approximants: -Al13Fe4, -AlFe and r3-Al3Ni2 were found to be main constituent phases in these pseudo-binary alloys. The formation of these constituent phases will follow the evolution of their corresponding e/a-constant lines in the Al-(Cu,Ni)-(Fe,Co) pseudo-ternary phase diagrams. The above result proves that the alloying of two QCs has effectively broken the quasiperiodic arrangement of icosahedral clusters, as a result the initial QC phases transform into their corresponding approximants.As-cast alloys in both groups were subsequently annealed at 750 for one hour to remove metastable phases. After annealing, the IQC and 3 phases were found to grow and the metastable DQC phase transforms into a mixture of r3 and . In addition, Al-Cu-Co DQC phase emerges in the IQC80DQC20 and IQC70DQC30 alloys after annealing. This phenomenon indicates the existence of icosahedral clusters in the IQC100-xDQCx alloys even after complete melting. The retained icosahedral clusters will act as basic clusters in future amorphous formation.The prepared IQC80DQC20 alloy was subsequently mixed with Zr to produce Zrx(IQC80DQC20)100-x alloys (x in wt.%). The result shows that with the addition of Zr, thestructures of the constituent phases become more and more complex. With 70wt.% Zr addition, the constituent phases has the most complex structure. These phases are all topologically close packed (TCP) phases. In their structures, not only Al-centered icosahedra but also Zr-centered close packed polyhedra can be found as basic clusters. This indicates that the addition of Zr has effectively increased the amount of close packed polyhedra in the alloy structure. This correlates with the structural characters of bulk metallic glasses.Amorphous ribbons with the composition of Zr70(IQC80DQC20)3o (Zr50Al32Cu10Fe5Co1.5Ni1.5) were produced. The amorphous alloy exhibits high glass forming ability and stability that are comparable to those of the Inoue alloyFollowing similar route, in the second alloy system, IQC was first alloyed with Ni. The IQC100-xNix (x in at.%) alloys exhibit simple cubic B2 structure. The further addition of Zr into the IQC70Ni30 and IQC50Ni50 alloys also result in a gradual increase of the complexity of the constituent phases' structures. Among other alloy, Zr4oNi27lQC33 alloy has the most complex constituent phases and the lowest melting points.Amorphous ribbons were subsequently produced at the Zr40Ni27IQC33 (Zr40Ni27Al20.4Cu8.4Fe4.2) composition. The produced amorphous alloy exhibits high glass forming abil...
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