Search

A structural reactive material (SRM) cylinder is considered here as a limiting case of a dense metallic energetic system in which a mixture of metal particles is consolidated to the theoretical maximum density excluding porosity, to possess both high energy density and mechanical strength. Dynamic fragmentation and free‐field explosion of a 103 mm inner diameter SRM cylinder charge is experimentally studied, with a wall thickness varying in a range of metal‐to‐explosive mass ratio M/C=1.3 to 4.0. Under explosive loading, the SRM cylinder produces a designated fragment size distribution divided into two groups: fine fragments with sizes on the order of 102 μm and below, and coarse fragments with sizes on the order ranging between 100‐101 mm. Prompt detonation shock‐induced reaction (DSIR) of the expanding cloud of high‐concentration fine fragments supplements the energy to enhance the primary blast as it propagates, while the coarse fragments form a high‐speed, high‐concentration metal momentum flux crossing the fireball and blast front to contribute to the total impulse loading to a nearby structure. Rapid impact‐induced reaction (IIR) of the secondary fragments from high‐speed coarse SRM fragments further enhances the reflected blast loading or generates a high interior explosion pressure as fragments perforate into the structure. The above distinctive characteristics of a unique hetero‐blast are coupled effectively in the near‐field range. [ABSTRACT FROM AUTHOR]

W-Zr alloy has the advantages of high density, high strength and high reaction potential, which can not only exert the excellent penetration ability of tungsten-based alloy, but also provide additional damage by using the oxidation reaction of zirconium. W-Zr alloys have shown great application potential in reactive fragment, armor-piercing projectiles, and small caliber projectiles, and have attracted attention both domestically and internationally. The preparation methods, mechanical properties, and reaction characteristics of W-Zr alloy reactive structural materials were summarized in this paper, especially focusing on the penetration ability and energy release characteristics. On the basis, it was proposed that the future development of W-Zr alloys should focus on the regulation of combustion characteristics of W and the improvement of plasticity. Additionally, there is still a lack of systematic research on the synergistic mechanism between the microstructure, mechanical properties, dynamic fracture, and reaction energy release of W-Zr alloys, which requires further improvement through a combination of experimental research and simulation calculations.

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

For investigating the mechanisms of microstructures and mechanical properties on energy-release capacity under high velocity impacting process of reactive structural materials (RSMs). Zr-Nb alloys with different Nb content were prepared via powder metallurgy. Both the α/β phase proportion and phase distribution vary with Nb content. The energy-release capacity under high-velocity impaction of Zr-Nb alloys shows an obvious difference. Micro-analyzing reveals that the smaller size of fragments after impaction is crucial for facilitating Zr reaction with oxygen, resulting in better energy-release capacity. However, the size of fragments after impaction is not only determined by the plasticity of alloys but also influenced by the microstructure. A continuous distribution of brittle α surrounding β is beneficial to controlling crack propagation path and forming fragments with small sizes. In the present work, the Zr-20 Nb alloy exhibits excellent energy-release capacity. [Display omitted] • Zr-Nb alloys with different plasticity&strength were prepared by powder metallurgy. • α phase surrounds β phase assist to form tiny fragments under impacting process. • Proper plasticity assists in the accumulation of adiabatic temperature rise. • Fragments with small size and high adiabatic temperature violently react with oxygen. • Zr-20 Nb alloy exhibits excellently comprehensive energy-release capacity. [ABSTRACT FROM AUTHOR]