Pressure effects on elastic properties and glass transition of Zr-, Pd-based bulk metallic glasses

The structures and properties of materials are profoundly altered under hig h pressure due to a large change of atom spacing, chemical bonding and Gibb s free energies. Therefore, materials with novel structures and properties call be created via a process known as pressure-induced phase transition. H ere we report the investigations of pressure effects on the elastic propert ies and the glass transition of Zr-, Pd-based bulk metallic glasses (BMGs), The elastic constants and the Debye temperatures, of a Zr41Ti14Cu12.5Ni10B e22.5C1 and a Pd39Ni10Cu30P21 BMGs are measured by using an ultrasonic tech nique, and their pressure dependence is exhibited. The equations of state ( EOS) of the two BMGs are established. The acoustic attenuation behaviors ar e also monitored with various pressure in the two BMGs, and a marked differ ence between the two BMGs is revealed, The effects of pressure-induced stru ctural relaxation on the glass transition of the Pd39Ni10Cu30P21 BMG are in vestigated by a temperature-modulated differential scanning calorimetry tec hnique. The pressure dependence of the reversible and irreversible glass tr ansition is explained.