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On the Evolution of Quasicrystalline and Crystalline Phases in Rapidly Quenched Al-Co-Cu-Ni Alloy

T. P. Yadav·N. K. Mukhopadhyay·R. S. Tiwari·O. N. Srivastava
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Abstract

The occurrence of stable decagonal quasicrystalline phase in Al-Co-Ni and Al-Cu-Co alloys through conventional solidification is well established. Earlier, we have studied the effect of Cu substitution in place of Co in the Al70 Co15Ni15 alloy. Here we report the structural/micro-structural changes with substitution of Cu for Ni in rapidly solidified Al-Co-Ni alloys. The melt-spun ribbons have been characterized using X-ray diffractometry (XRD), Scanning and transmission electron microscopy (SEM & TEM). With an increase in Cu content in the melt spun Al70 Co15Cux Ni15-x (x=0 to 15) alloys, the relative amount of the decagonal phase decreased up to 10 at% of Cu. At this composition the quaternary alloy showed the coexistence of decagonal quasicrystal and superstructure of tau 3 vacancy ordered crystalline phases. The decagonal phase containing Cu showed more disordering compared to Al-Co-Ni alloys. The implication of the structural / microstructural changes due to Cu substitution in stable decagonal quasicrystal will be discussed

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T. P. Yadav, N. K. Mukhopadhyay, R. S. Tiwari, O. N. Srivastava. 2006-10-12. On the Evolution of Quasicrystalline and Crystalline Phases in Rapidly Quenched Al-Co-Cu-Ni Alloy. https://arxiv.org/abs/cond-mat/0610347

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