In order to enlarge the crater diameter of shaped charge jet penetration into steel targets, this paper investigates the penetration and cratering characteristics of steel targets by shaped charge jets from titanium alloy liners. Titanium alloy shaped charge liners are prepared separately with mechanical processing and selective laser melting (SLM), and pulsed X-ray radiography is used to identify jet formation characteristics. Jet formation is numerically simulated by AUTODYN-3D, and steel target penetration tests are carried out at a short jet stand-off distance. The results show that AUTODYN-3D can realistically simulate jet formation from titanium alloy liners and that the SLM-processed liner exhibits better penetration performance than the mechanically processed liner. The existing cratering formula of jet penetration is modified to make it consistent with the aperture variations of jet penetration from titanium alloy-lined shaped charges at a short stand-off distance. The findings of this study are expected to provide technical and theoretical support for research on the penetration characteristics of the jets from titanium alloy-lined shaped charges.

This study investigated the deformation behavior of the Mo-10Ta alloy with a strain rate range of 10²–10⁵ s⁻¹. The Split Hopkinson pressure bar (SHPB) experiments were conducted to investigate the influence of deformation conditions on the stress-strain relationship and strain rate sensitivity of the material within a strain rate range of 0.001–4500 s⁻¹. The Shaped Charge Jet (SCJ) forming experiments under detonation loading was conducted to clarify the dynamic response and microstructure evolution of the material within an ultra-high strain rates range of 10⁴–10⁵ s⁻¹. Based on the stress-strain relationship of Mo-10Ta alloy at high temperature (286–873 K) and high strain rate (460–4500 s⁻¹), the influence of temperature and strain rate on the activation energy Q was analyzed. The results indicate that the material strain rate sensitivity increased with the increase in strain rate and strain. Meanwhile, the activation energy Q decreased as the temperature and strain rate increased. The plasticity of the Mo-10Ta alloy under the condition of SCJ forming was substantially enhanced compared with that under quasi-static deformation. The material grain was also refined under ultra-high strain rate, as reflected by the reduction in grain size from 232 μm to less than 10 μm.

Colored polymer microspheres have attracted significant attention in both academia and industry due to their unique optical properties and extensive application potential. However, achieving a uniform distribution of dyes within these microspheres remains a challenge, particularly when heavy concentrations of dye are used, as this can lead to aggregation or delamination, adversely affecting their application. Additionally, many dyes are prone to degradation or fading when exposed to light, heat, or chemicals, which compromises the long-term color stability of the microspheres. Consequently, the preparation of colored polymer microspheres with high stability continues to be a significant challenge. This review offers a comprehensive overview of the preparation techniques for colored polymer microspheres and their dyeing mechanisms, introducing the fundamental concepts of these microspheres and their applications in various fields, such as biomedicine, optical devices, and electronic display technologies. It further presents a detailed discussion of the different preparation methods, including physical adsorption, chemical bonding, and copolymerization. The advantages, limitations, and potential improvements of each method are explored, along with an analysis of the interactions between dyes and the polymer matrix, and how these interactions influence the properties of the microspheres, including their color uniformity, stability, and durability. Finally, the review discusses future perspectives on the development of colored polymer microspheres, highlighting the advancement of novel materials, innovations in preparation technology, and the exploration of potential new application areas.

To investigate the plastic deformation (PD) response of a liner material during the shaped-charge jet (SCJ) formation process, the state of motion of liner material and the pattern of change in its deformation environment under explosive loading were theoretically analyzed and modeled. The distribution patterns of the characteristic PD parameters (that is, strain, strain rate, temperature, and flow stress) of the jet at any given time were theoretically predicted. The distribution patterns of the characteristic PD parameters of jets formed from two materials, namely, oxygen-free high-thermal-conductivity copper (OFHC-Cu) and molybdenum (Mo), during their formation process were theoretically analyzed. A series of experimental and numerical simulation studies were conducted to examine the accuracy of the theoretical predictions. As per the results, the developed theoretical model is effective in predicting the one-dimensional distribution of the characteristic PD parameters in the direction of jet formation. At any given time, the distribution of the characteristic PD parameters varies considerably between different parts of the jet. There is no significant difference in the distribution of the strain and strain rate between the jets formed from the two materials in the presence of the same warhead structure. A theoretical analysis predicted average temperatures of 804 and 2277.8 K and average flow stresses of 193.1 and 344.3 MPa for the OFHC-Cu and Mo jets, respectively. A hardness analysis of the jet fragments revealed average strengths of 144.32 and 286.66 MPa for the OFHC-Cu and Mo jets during their formation process, respectively. These results differed by 34% and 20% from the corresponding theoretical predictions.

With the widespread application of tagging materials, existing chemical tagging materials exhibit limitations in stability and detection under field conditions. This study introduces a novel magnetic detection scheme. Hydrophilic material-modified Fe₃O₄ nanoparticles (COOH-PEG@Fe₃O₄ NPs) were synthesized using the co-precipitation technique. The content of Fe₃O₄ nanoparticles in the magnetic tagging liquid can reach up to 10 wt% and remain stable in an aqueous phase system for seven days. This research details the preparation process, the characterization methods (IR, ¹HNMR, EDX, XRD, SEM, TEM, VSM, DLS), and the performance effects of the materials in magnetic tagging. Experimental results indicate that COOH-PEG@Fe₃O₄ NPs exhibit high remanence intensity (Br = 1.75 emu/g) and considerable stability, making it possible to quickly detect tagged liquids in the field using portable flux meters and optical pump magnetometers. This study provides new insights into the design and application of magnetic tagging materials, making it particularly suitable for long-term tagging and convenient detection in field scenarios.