Highly energetic and flammable metallic glasses
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ly 2020 Vol. 63 No. 7: 276112 https://doi.org/10.1007/s11433-019-1527-0
Highly energetic and flammable metallic glasses 1,2
1,2,3*
BangSheng Yu , YongHao Sun
, HaiYang Bai
1,2,3
1,2,3*
, and WeiHua Wang
1
2
Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China; 3 Songshan Lake Materials Laboratory, Dongguan 523808, China Received December 24, 2019; accepted February 13, 2020; published online March 25, 2020
Energetic materials are solids that release a large amount of energy in combustion. The evaluation depends on both combustion heat and ignition temperature. Conventional non-metallic materials have low ignition temperature but small combustion heat, whereas metals have large combustion heat but high ignition temperatures. We show that many metallic glasses, combining the merits of both metals and non-metals, have large combustion heat, approximately twice that of the non-metals, and low ignition temperature that is several hundreds of Kelvin lower than that of the metals. The ease in igniting metallic glass results from the low thermal conductivity of the materials and the storage of energy in their liquid-like atomic structure. Metallic glass ribbons outweigh metallic nanoparticles due to their high production efficiency, low cost and nontoxicity. The findings suggest that metallic glasses are alternative energetic materials. metallic glass, energetic particles, combustion, fast ignition, nanoscale materials PACS number(s): 71.23.Cq, 96.50.Vg, 47.70.Pq, 52.57.Kk, 61.46.-w Citation:
1
B. S. Yu, Y. H. Sun, H. Y. Bai, and W. H. Wang, Highly energetic and flammable metallic glasses, Sci. China-Phys. Mech. Astron. 63, 276112 (2020), https://doi.org/10.1007/s11433-019-1527-0
Introduction
Energetic materials, releasing large heat in combustion, are evaluated by the combustion heat, i.e. the energy released by one gram of the material in combustion. Non-metals, broadly applied as explosives or fuels, have typical combustion heat 3 −1 of (3-6)×10 J g [1,2]. However, despite more nitrogen atoms are synthesized into macromolecules [3], the combustion heat of these compounds might have reached a ceiling. To further enhance the combustion heat, “go metallic” seems to be a solution since metals have larger combustion heat than non-metals. Metals like aluminum (Al) and magnesium (Mg) have *Corresponding authors (YongHao Sun, email: [email protected]; WeiHua Wang, email: [email protected])
3
4
−1
large combustion heat, ranging from 3×10 to 3×10 J g [4,5] that are ideal for energetic applications. The problem is their high ignition temperatures. For example, although the 4 −1 combustion heat of Al is promisingly large, i.e. ~3×10 J g , Al ignites at ~2100 K [6], far higher than that of the nonmetals. The current strategy to reduce the ignition temperature is to minimize the sample size: when metals are powdered, their ignition and combustion efficiency are improved [6,7]
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