Microstructural inhomogeneities introduced in a Zr-based bulk metallic glass upon low-temperature annealing

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 491; no. 1; pp. 124 - 130
• Main Authors: Van Steenberge, N., Concustell, A., Sort, J., Das, J., Mattern, N., Gebert, A., Suriñach, S., Eckert, J., Baró, M.D.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.09.2008; Elsevier
• Subjects: Applied sciences; Elasticity. Plasticity; Exact sciences and technology; Heat treatment; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metallic glass; Metals. Metallurgy; Microstructure; Plasticity; Heat treatment; Microstructure; Metallic glass; Plasticity; High strain; Annealing; Embrittlement; Zirconium alloy; Glass transition; Metallic glasses; Transition metal alloy; Shear deformation; Yield strength; Localization
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2008.01.083

Due to their exceptionally high yield strength and yield strain as compared to conventional metallic materials, bulk metallic glasses (BMGs) represent a class of promising engineering materials for structural applications. However, inhomogeneous deformation and severe shear localization at ambient temperature often lead to early failure and limit their reliability as structural materials. Heat treatments around the glass transition temperature ( T g) generally aggravate the intrinsic brittleness of BMGs. In this paper, we report on the evolution of a nanoscale inhomogeneous microstructure upon low-temperature annealing in a Zr 55Cu 30Al 10Ni 5 BMG. This important outcome is explained by the experimentally observed tendency for chemical decomposition between Cu and Zr of the investigated amorphous system and is in accordance with literature data on various Zr–Cu-based amorphous alloys. Finally, these local fluctuations influence the plasticity of BMGs beneficially, in contrast of the generally accepted embrittlement upon annealing.