Viscosity measurements of Zr55Cu30Al10Ni5 and Zr50Cu40-xAl10Pdx(x= 0, 3 and 7 at.%) supercooled liquid alloys by using a penetration viscometer

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 449-451; pp. 203 - 206
• Main Authors: MAEDA, S, YAMASAKI, T, YOKOYAMA, Y, OKAI, D, FUKAMI, T, KIMURA, H. M, INOUE, A
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Amsterdam Elsevier 25.03.2007
• Subjects: Condensed matter: structure, mechanical and thermal properties; Diffusive momentum transport (including viscosity of liquids); Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Glass transitions; Physics; Specific phase transitions; Transport properties of condensed matter (nonelectronic); Viscosity; Crystallization; Supercooled liquid; Palladium additions; Penetration viscometer; Heat treatments; Glass formation; Glass transition; Supercooled liquids; Metallic glasses; Liquid alloys; Oxygen contamination; Zr55Cu30Al10Ni5; Arrhenius equation; Activation energy; Zirconium alloys
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2006.02.288

Viscosity of Zr55Cu30Al10Ni5 and Zr50Cu40-xAl10Pdx (x=0, 3 and 7at.%) supercooled liquid alloys having bulk metallic glass forming ability has been measured by using a penetration viscometer with a cylindrical probe under high speed heating conditions at heating rates between 20 and 400K/min in the temperature range from the glass transition temperatures (Tg) up to above the crystallization temperatures. Effect of Pd addition on the viscosity of Zr-base supercooled liquid alloys has been also examined. The viscosity of these alloys decreased with increasing the heating rate and tended to saturate at the heating rate of 200K/min and above. These viscosities can be well represented by the Arrhenius relation. The activation energy for viscous flow for Zr55Cu30Al10Ni5 supercooled liquid alloys was about 350kJ/mol. In the Zr50Cu40-xAl10Pdx (x=0, 3 and 7at.%) alloys, the viscosities increased with increasing the Pd-content, while the activation energy for viscous flow decreased from 337 to 276kJ/mol.