A thermodynamic model for nanocrystallization in bulk metallic glasses |
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Authors: | PJ Desre |
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Institution: | 1. Laboratory for Unconventional Electronics and Photonics, Department of Physics , National Institute of Technology , Calicut, Kerala 673601, India predeep@nitc.ac.in ppredeep@gmail.com;3. Laboratory for Unconventional Electronics and Photonics, Department of Physics , National Institute of Technology , Calicut, Kerala 673601, India |
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Abstract: | The structural complexity of glass-forming alloys, which generally contain more than three components, can lead by partial crystallization during annealing to a dispersion of nanocrystals in an amorphous matrix, giving the material a very high mechanical strength. In the present study, the evolution of the driving force for crystallization is expressed as a function of the composition and the chemical potentials of the components. Application to Zr60Al10Cu30 and Zr60Al10Cu20Pd10 bulk metallic glasses shows that the first crystallization step leads to a metastable equilibrium between nanocrystals of an intermetallic and a percolating amorphous phase. The effects of the number of components and of chemical bonding on the fraction crystallized is analysed and discussed. |
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Keywords: | high-temperature superconductivity composite materials X-ray diffraction YBCO Raman spectroscopy electromagnetic shielding |
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