| Abstract |
| Formation range of the amorphous phase in melt-spun Al-Ni-Y alloy system was investigated. The amorphous single phase was obtained when the content of solute(Ni+Y) is more than 10at%. Then, the addition of Y atom was more effective than that of Ni atom. The crystallization of amorphous Al90-xNi10Yx, (x=2, 4, 6 at%) alloys proceeded through two or three stages. I.e., by forming Al phase at the first stage of the low temperature side and by forming intermetallic compounds (Al3Ni, Al3Y) at the 2nd or 3rd stages of the high temperature side. The resulting Al particles smaller than l5nm and compounds larger than 50 nm in diameter were uniformly distributed in the amorphous matrix. The ultimate tensile and yield strengths of their alloys kept high value with a slight decrease from room temperature to 400K. Elongation Increased significantly from 2% at room temperature to over 20% at temperatures higher than crystallization temperature. DSC analysis shows that such a large elongation was originated from the precipitation of the crystalline phase. On the other hand, In Al88Ni10Y2 and Al86Ni10Y4 alloys which do not exhibit glass transition phenomenon, the deformation occurred through the shear deformation mode. However, with occurrence of glass transition (Al84Ni10Y6 alloy). the deformation mode was changed viscoelastic alloy. |
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| Key Words |
| Amorphous, High-temperature property, Crystallization, Al particle, Exothermic reaction, Glass transition Phenomenon, Shear deformation, Viscoelastic deformation |
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