A thermodynamic model for nanocrystallization in bulk metallic glasses

2019-11-09 02:15:25

alloys crystallization amorphous chemical glasses

责任者: Desre, P.J. 单位: Lab. de Thermodynamique et Physicochimie Metall., Inst. Nat. Polytech., Grenoble, France 来源出处: Philosophical Magazine Letters(Philos. Mag. Lett. (UK)),2000/06/,80(6):401-9 摘要: 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 关键词: aluminium alloys;annealing;bonds (chemical);copper alloys;crystallisation;glass structure;mechanical strength;metallic glasses;nanostructured materials;palladium alloys;thermodynamics;zirconium alloys;thermodynamic model;nanocrystallization;bulk metallic glasses;structural complexity;glass-forming alloys;partial crystallization;annealing;dispersion of nanocrystals;amorphous matrix;very high mechanical strength;composition;chemical potentials;Zr60Al10Cu30;Zr60Al10Cu20Pd10;metastable equilibrium;percolating amorphous phase;chemical bonding