Effect of Sn on microstructure and mechanical properties of (Ti–Cu)-based bulk metallic glasses

Abstract

A Ti₄₃Zr₇Cu₄₃Ni₇ bulk metallic glass (BMG) exhibits a plastic strain of less than 0.2% under room-temperature compression. However, a Ti₄₅Zr₅Cu₄₀Ni_7.5Sn_2.5 BMG developed by addition of Sn to Ti₄₃Zr₇Cu₄₃Ni₇ shows a significant improvement of ∼14.8% to the plastic strain with work hardening. Microstructural comparison of these BMGs reveals that the addition of Sn leads to formation of nano-scale chemical heterogeneities throughout the material. These nano-scale chemical fluctuations play an important role in enhancing the plastic strain of (Ti–Cu)-based BMGs.

Acknowledgements

The authors thank I. S. Hwang (Daegu, South Korea), and M. Calin, U. Kunz, S. Scudino, R. Theissmann, S. Venkataraman, W. Xu, P. Yu, L. C. Zhang and W. Y. Zhang (TU Darmstadt) for technical assistance and stimulating discussions. Support from the Korean Ministry of Commerce, Industry and Energy for the development of structural metallic materials and parts with super strength and high performance is gratefully appreciated. The authors are also grateful for financial support provided by the European Union–RTN on ‘ductile BMG composites’ (MRTN-CT-2003-504692) for structural investigations and mechanical testing during K. B. Kim's stay in Germany.