Established and already commercialized energetic materials, such as those based on Ni/Al for joining, lack the adequate combination of high energy density and ductile reaction products. To join components, this combination is required for mechanically reliable bonds. In addition to the improvement of existing technologies, expansion into new fields of application can also be anticipated which triggers the search for improved materials. Here, we present a comprehensive characterization of the key parameters that enables us to classify the Ru/Al system as new reactive material among other energetic systems. We finally found that Ru/Al exhibits the unusual integration of high energy density and ductility. For example, we measured reaction front velocities up to 10.9 (±0.33) ms−1 and peak reaction temperatures of about 2000 °C indicating the elevated energy density. To our knowledge, such high temperatures have never been reported in experiments for metallic multilayers. In situ experiments show the synthesis of a single-phase B2-RuAl microstructure ensuring improved ductility. Molecular dynamics simulations corroborate the transformation behavior to RuAl. This study fundamentally characterizes a Ru/Al system and demonstrates its enhanced properties fulfilling the identification requirements of a novel nanoscaled energetic material.
Due to the peculiar nature of the atomic order in quasicrystals, examining phase transitions in this class of materials is of particular interest. Energetic particle irradiation can provide a way to modify the structure locally in a quasicrystal. To examine irradiation-induced phase transitions in quasicrystals on the atomic scale, we have carried out molecular dynamics simulations of collision cascades in CaCd 6 quasicrystal cubic approximant with energies up to 10 keV at 0 and 300 K. The results show that the threshold energies depend surprisingly strongly on the local coordination environments. The energy dependence of stable defect formation exhibits a power-law dependence on cascade energy, and surviving defects are dominated by Cd interstitials and vacancies. Only a modest effect of temperature is observed on defect survival, while irradiation temperature increases lead to a slight increase in the average size of both vacancy clusters and interstitial clusters.
The initial steps of Ge nanovoids formation have been studied. Two step energetic ion irradiation processes was used to fabricate novel and distinct embedded nanovoids within bulk Ge. The formation of voids in amorphous-Ge (a-Ge) and their size, and shape evolution under ultra-fast thermal spike within ion track of swift heavy ion, is meticulously expatiated using experimental and theoretical approaches. The 'bow-tie' shape of void formed in single ion track tends to attain spherical shape as the ion tracks overlap at about 1×10 12 ions cm-2 and the void assumes prolate spheroid shape with major axis along the ion trajectory at sufficiently high ion fluences. Small angle X-ray scattering can provide information about primary stage of void formation hence this technique is applied for monitoring simultaneously their formation and growth dynamics. The results are supported by transmission (XTEM) and scanning (XSEM) electron micrographs. The multi-timescale theoretical approach corroborate the experimental findings and relate the bow-tie shape void formation to density variation as a result of melting and resolidification of Ge within thermal spike generated along ion track plus non-isotropic stresses generated towards the end of the thermal spike.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.