Flash Joule heating for ductilization of metallic glasses

• Published in: Nature communications Vol. 6; no. 1; p. 7932
• Main Authors: Okulov, I. V., Soldatov, I. V., Sarmanova, M. F., Kaban, I., Gemming, T., Edström, K., Eckert, J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 29-07-2015; Nature Publishing Group; Nature Pub. Group
• Subjects: 639/301/119/1002; 639/301/923/218; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms8932

Metallic glasses (MGs) inherit their amorphous structure from the liquid state, which predetermines their ability to withstand high loads approaching the theoretical limit. However, the absence of slip systems makes them very sensitive to the type of loading and extremely brittle in tension. The latter can be improved by precipitation of ductile crystals, which suppress a catastrophic propagation of shear bands in a glassy matrix. Here we report a novel approach to obtain MG-matrix composites with tensile ductility by flash Joule heating applied to Cu
47.5
Zr
47.5
Al
5
(at.%) metallic glass. This homogeneous, volumetric and controllable rapid heat treatment allows achieving uniformly distributed metastable B2 CuZr crystals in the glassy matrix. It results in a significant tensile strain of 6.8±0.5%. Moreover, optimized adjustment of the heat-treatment conditions enables tuning of microstructure to achieve desired mechanical properties.
Metallic glasses (MG) have higher yield strengths than crystalline alloys but at the same time are very brittle, which has hampered practical applications. Here, the authors use flash Joule heating to design a MG-matrix composite with a uniform distribution of ductile crystals, improving mechanical properties.