Amorphous alloys in the Cu–Hf–Ti system

• Published in: Journal of alloys and compounds 2008-07, Vol.459 (1), p.160-162
• Main Authors: Choi-Yim, Haein, Conner, R.D.
• Format: Article
• Language: English
• Subjects: Applied sciences; Bulk metallic glass; Condensed matter: structure, mechanical and thermal properties; Deformation and plasticity (including yield, ductility, and superplasticity); Elasticity. Plasticity; Exact sciences and technology; Glass forming ability; Mechanical and acoustical properties of condensed matter; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Mechanical properties of solids; Metals. Metallurgy; Physics; Thermodynamic properties
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2007.04.264

Good bulk glass forming alloys can be found over a wide range of compositions in the neighborhood of Cu 60Hf 25Ti 15. The glass forming ability, thermal and mechanical properties of the Cu–Hf–Ti system is examined for alloys in the composition range of 57.5 < Cu < 62.5, 22.5 < Hf < 28.75, 11.25 < Ti < 17.5 (at.%). These alloys typically have strength ∼2 GPa, Hv ≥ 600, T g ∼ 450 °C, and Δ T ∼ 50 °C, and these properties are uniform independent of particular composition. Increasing Hf content while decreasing Ti increases the density and liquidus temperature of Cu–Hf–Ti alloys, while increasing Cu content decreases glass forming ability. The effect on GFA of small additions of Si, Ni, Y and Ta was evaluated. A 2 at.% addition of Y improved the GFA of the most robust bulk glass forming alloy in this series, Cu 57.5Hf 27.5Ti 15.