Metallic glass formation in the binary Cu–Hf system

• Published in: Journal of materials science Vol. 48; no. 4; pp. 1819 - 1825
• Main Authors: Figueroa, I. A., Plummer, J. D., Lara-Rodriguez, G. A., Novelo-Peralta, O., Todd, I.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.02.2013; Springer; Springer Nature B.V
• Subjects: Alloy systems; Amorphous materials; Analysis; Binary alloys; Binary systems; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Copper; Crystallography and Scattering Methods; Glass formation; Glass transition temperature; Liquidus; Materials Science; Melt spinning; Metallic glasses; Polymer Sciences; Predictions; Ribbons; Solid Mechanics; Suction; Tapes (metallic); Thermal properties; Thermodynamic properties; Thickness; Glass Formation; Metallic Glass; Bulk Metallic Glass; Wheel Speed; Glassy Phase
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-012-6946-5

Glass formation, structure and thermal properties of alloys in the binary Cu 100− x Hf x alloy system, where x  = 25–50 at.%, are reported and discussed. This work also presents a comparison between copper casting techniques, from thick melt-spun ribbons to suction cast cylindrical rods, and the prediction of critical diameter, d c , based on maximum ribbon thickness, x c . Ribbons of Cu 60 Hf 40 and Cu 65 Hf 35 exhibited a fully glassy phase up to a thickness of 170 μm. Suction casting lead to an increase in the largest diameter over which both alloys could be cast, in comparison to melt-spun ribbons, and remain amorphous, with Cu 65 Hf 35 showing a large critical diameter of 1 mm. This result is rationalised by a lower liquidus temperature, T l , which maximises the reduced glass transition temperature, T rg , and also correlates closely with the eutectic point. Finally, there were remarkable similarities between the Miedema model and the efficient packing model for predicting the range for metallic glass formation in this binary system.