Enhanced glass forming ability and plasticity in Mg-based bulk metallic glasses

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2007-03, Vol.449, p.225-229
• Main Authors: Park, E.S., Kyeong, J.S., Kim, D.H.
• Format: Article
• Language: English
• Subjects: Applied sciences; Bulk metallic glass; Condensed matter: structure, mechanical and thermal properties; Elasticity. Plasticity; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; GFA; Glass transitions; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Physics; Plasticity; Specific phase transitions
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2006.03.142

In the present study, the effect of small substitution in Mg 65Cu 25Gd 10 (at.%) alloy has been investigated for two purposes, i.e.: (1) for improvement of glass forming ability (GFA) and (2) for enhancement of compressive plasticity possibly. The Mg 65Cu 7.5Ni 7.5Ag 5Zn 5Y 5Gd 5 bulk metallic glass (BMG) with diameter of 14 mm is successfully fabricated by conventional copper mold casting method in air atmosphere, which is the highest GFA among those previously reported for Mg-based alloys. The significantly improved GFA of the Mg–Cu–Ni–Zn–Ag–Y–Gd alloys can be properly represented by T rg, γ and ɛ parameters. Although general Mg-based BMG show a little and no plasticity under compressive loading, the addition of element having positive enthalpy of mixing with constitutive element such as Be, Ag and Y increases the plasticity in a limited composition range.