THERMODYNAMIC ASPECTS OF METASTABLE-PHASE FORMATION

The behaviour of thermodynamic properties in metallic liquid glass-forming systems is reviewed. It is shown that they are compatible with the hypothesis of progressive ordering on cooling. Trends for the ideal glass-transition temperature are calculated as a function of composition for different types of phase diagram. The occurrence of amorphization by solid-state reaction is described on the basis of favourable thermodynamic conditions. Evidence for high-pressure amorphization is collected and different reaction mechanisms are discussed. Thermodynamic quantities for quasicrystalline phases are estimated and compared with those for glassy and equilibrium phases. © 1990 Taylor & Francis Ltd.