Theoretical analysis of the glass-forming behaviour of Ni-Zr and Ni-Zr-Fe alloys
The metastable free energy diagram of the Ni-Zr alloy at 300 K was calculated using Miedema's theory. A previous extension of the theory to ternary systems was further developed and used to calculate the free energies of the metastable amorphous phase and crystalline solid solutions of the Ni-Z...
Guardado en:
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2000
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_13689290_v11_n3_p299_DeTendler http://hdl.handle.net/20.500.12110/paper_13689290_v11_n3_p299_DeTendler |
| Aporte de: |
| Sumario: | The metastable free energy diagram of the Ni-Zr alloy at 300 K was calculated using Miedema's theory. A previous extension of the theory to ternary systems was further developed and used to calculate the free energies of the metastable amorphous phase and crystalline solid solutions of the Ni-Zr-Fe system at 300 K. The results of the calculations are compared with experimental data taken from the literature. The metastable free energy diagram of Ni-Zr is consistent with the measured glass-forming range. It allows to predict the succession of phases - amorphous alloys, crystalline solid solutions and intermetallic compounds - observed in rapidly quenched Ni-Zr alloys and in solid-state interdiffusion in Ni-Zr composites. In the ternary system Ni-Zr-Fe, intersections of the calculated free-energy surfaces of solid solutions together with that of the amorphous phase define an extended glass-forming composition range that contains the observed Ni-Zr-Fe glass compositions. The relative positions of the free-energy surfaces of the bcc solid solution and the amorphous phase and the region of metastable equilibrium between amorphous alloy and α-Zr solid solution provide the basis for interpreting the appearance of different phases in experiments on partial amorphization of Zr-rich, Ni-Zr-Fe melt-quenched alloys. |
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