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Metal matrix composites tiles based on Ti-6Al-4V (Ti64) alloy, reinforced with 10, 20, and 40 (vol%) of either TiC or TiB particles were made using press-and-sinter blended elemental powder metallurgy (BEPM) and then bonded together into 3-layer laminated plates using hot isostatic pressing (HIP). The laminates were ballistically tested and demonstrated superior performance. The microstructure and properties of the laminates were analyzed to determine the effect of the BEPM and HIP processing on the ballistic properties of the layered plates. The effect of porosity in sintered composites on further diffusion bonding of the plates during HIP is analyzed to understand the bonding features at the interfaces between different adjacent layers in the laminate. Exceptional ballistic performance of fabricated structures was explained by a significant reduction in the residual porosity of the BEPM products by their additional processing using HIP, which provides an unprecedented increase in the hardness of the layered composites. It is argued that the combination of the used two technologies, BEPM and HIP is principally complimentary for the materials in question with the abilities to solve the essential problems of each used individually. [ABSTRACT FROM AUTHOR]

The damage stages of the ballistic impact effect on both thin and thick laminated composites were investigated. Thin and thick laminated composite plates were produced with unsymmetrical cross-ply [0/90], [–45/+45], and [30/60] layups consisting of 16 and 50 unidirectional layers, respectively. Ballistic tests of the composite plates were carried out by means of a single-stage gas gun system at different velocities in the range from 447 to 861 m/s. The thin composite plates were more damaged than the thick plates at ballistic tests with the same velocity. Relatively small strains were observed at low-velocity impact while the projectile rebounded in all thick specimens. All thick plate specimens, except the plates with [–45/+45] layup, were perforated at high velocity impacts. Tests showed an increase in the shear stress between layers with increasing projectile velocity. [ABSTRACT FROM AUTHOR]

B 4 C-TiB 2 composites with classical 75/25 vol ratio were sintered by pressureless sintering with and without gas pressure application in the final stage of densification, using a novel prototypal furnace. A small fraction of WC was introduced through high energy milling of the starting powders with WC-Co spheres. High energy milling facilitated the densification thanks to incorporation of WC impurities acting as sintering aid, and size reduction of the starting powders. Strength, stiffness and toughness of the ceramic densified at 2050 °C via gas pressure sintering were even better than hot pressed composites at 1900 °C. Depth of Penetration tests on plates with 3–5 mm thickness demonstrated that the gas pressure sintered material had a superior performance compared to the hot pressed one. This work also revealed that hardness was not the property spotting the best ballistic performance. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department 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.)

The results of studying the protective (barrier) properties of oxide and nitride coatings against hydrogen penetration during thermohydrogen treatment (THT) are summarized, and the laws of formation of a linearly varying gradient structure in a VT6 titanium alloy are revealed. The dispersed α + β structure that forms on the alloy surface as a result of THT is found to cause high strength properties, and the coarse-lamellar structure in the center that forms at the center provides a high impact toughness. 12.5-mm-thick VT6 alloy plates with a linearly changing gradient structure are shown to exhibit good dynamic resistance when fired with 5.45- and 7.62-mm shell bullets with a steel core. [ABSTRACT FROM AUTHOR]

The silicon carbide (SiC)/metal composite armors with the composite cover on the front of the SiC plate were impacted by 12.7mm armor piercing incendiary (API) projectiles at velocities from 412.6m/s to 802.2m/s. The resulting projectile core and ceramic fragments were collected and then screened through a range of standard sieving screens. The mass distributions of fragments produced by projectile and ceramic impacting each other were obtained. The failure mechanism of the rigid-brittle core of 12.7mm API projectile after impacting SiC/metal composite armor was studied by examination of the failed core. The results show that the cumulative mass of core and ceramic fragments follow the Schuhmann distribution law. With the increase of impact velocity, the mass proportion of small core fragments increases, while for ceramic fragments, the mass proportion of fragments in different fractions does not change. The failure mechanism of the large equivalent diameter fragment ( >8mm) is tensile brittle fracture mainly. In contrast, the local plastic shear fracture exists on the fragments with an equivalent diameter of less than 2mm. [ABSTRACT FROM AUTHOR]

This work investigates the effect of hybridization and stacking sequence on the ballistic impact response of S2-glass/aramid/epoxy laminates. Different laminates were manufactured by vacuum infusion, one with only aramid fabrics (12 layers, K12), two with only S2-glass fabrics (12 or 18 layers, Gl12 and Gl18) and five interply hybrids (Gl3K9, [GlK]6, K6Gl6, Gl6K6, Gl9K3). Ballistic tests were performed according to EN1522- FB3, with the.357 Magnum FMJ projectile. The ballistic curves were determined to obtain the ballistic limit velocity (VBL), and in-plane damage area and through-the-thickness damage were analyzed. For the impact at 430 m/s, all laminates were perforated, and the Gl18 exhibited greater specific absorbed energy (26.6 J.m2/kg), with lower thickness and in-plane damage than the K12 (22.6 J.m2/kg) with a similar areal density (≈0.77 g/cm2). No significant differences in ballistic limits (pairing effect) were observed for the [GlK]6, Gl6K6 and K6Gl6 hybrids, and the Gl3K9 hybrid exhibited a positive hybrid effect. The areal density of laminates has shown a great influence on the final ballistic response. The results have shown that hybridization of aramid composites with S2-glass may enhance the impact absorption capability of hard composite armors, however, the ballistic limit velocity, which is a crucial parameter to assess ballistic shield performance, reduced. [ABSTRACT FROM AUTHOR]

The influence of additional heat hardening with the use of fast heating during austenitization on the armour resistance of high-strength sheet metal of protective purpose, made of medium-alloyed steel, is investigated. As established, the high-speed heat treatment by hardening and low tempering of slabs from rolled sheet with a thickness of 6 mm increases its ductility with unchanging the 4th class of leaves armour resistance. In addition to the possible inheritance of the deformation substructure, the increase in ductility after high-speed heat treatment while maintaining strength is due to significant grinding of the grain structure of steel. [ABSTRACT FROM AUTHOR]

The alloy Ti-6Al-4V and composites on its base reinforced with 5 to 80% vol. TiC are manufactured by press-and-sinter approach using TiH2, Al-V master alloy and TiC powder blends. Increase in TiC content up to 40% provides effective structure consolidation and continuous rise of material hardness. Composites fabricated at higher than 40% TiC content demonstrate insufficient integrity of the sintered structure due to excessive porosity. Using these data, 3 and 4 layers plates consisted of Ti-6Al-4V alloy and composites on its base containing from 10% to 40% TiC are made. Fabricated plates with dimensions of 90×90 mm and a thickness of 11-32 mm demonstrate complete integration between the layers and are suitable for the ballistic examination. Performed ballistic tests reveal an enhanced resistance of multilayered plates against piercing by various bullets types, which exceeds the performance by 7-40% when compared to the conventional Ti-6Al-4V alloy in terms of the specific kinetic energy required for the plate piercing. Kinetic energy of bullets is mainly dissipated by the deformation of the hard surface composite layers with 20% and, especially, 40%TiC, leaving not much energy for bullet to penetrate deep into subsequent ductile alloy layer. [ABSTRACT FROM AUTHOR]

Spark plasma sintering and a standard sintering method are used to manufacture ceramic plates with a diameter of 30 mm from aluminum oxide powder with a fraction size approximately equal to 3 µm. Dynamic strength of the ceramics obtained is studied. Dynamic loading is carried out by a hardened steel impactor. It is shown that energy dissipation in a material obtained using spark plasma sintering is substantially larger than that in a material produced using standard sintering, which means that it is more resistant to dynamic loads. [ABSTRACT FROM AUTHOR]

Despite the intensive development of plastics and composite materials in the case of armours employed to protect vehicles, armour steel remains a material commonly and effectively used. This is especially evident in the base armour of armoured vehicles, where the body is made of welded armour steel plates. However, the area of joining both the weld and the heat affected zone are sensitive areas with the reduced protective capability. In the case of laser welding in comparison with methods such as shielded metal arc welding and gas metal arc welding, it is possible to narrow down the above mentioned areas. The paper presents the results of research on the protective capability of welded zone of armour steel plates with a hardness of 500 HB. In the first part of the work, in order to select the proper parameters for the bonding process, different connection variants were made and their microstructure and selected mechanical properties were analysed. After selecting the best variant of the welding process, samples (200 mm × 200 mm) consisting of two welded plates with dimensions 100 mm × 200 mm were made for testing. The thickness of the plates was selected in such a way that in the areas outside the bonding zone, the lack of complete perforation by the projectiles used in the tests is guaranteed. The samples were shot at the weld location and at different distances from the weld to verify, for the chosen method of joining steel plates, if the welded armour loses its protective capability and, possibly, how wide this area may be. [ABSTRACT FROM AUTHOR]

Copyright of Progress in Physics of Metals / Uspehi Fiziki Metallov is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U 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.)

Several three-dimensional scanning methods have been developed and improved over the past 40 years. The peculiarities of each technique, associated with the computational advances of the period, allowed the increasing application and diffusion of the technology in several sectors, among them those related to metrology in ballistics and the testing of protective materials. The specific goal of such ballistic tests is to estimate the depth of indentation caused by projectiles. In particular, this study presents a comparative analysis between two three-dimensional optical scanning methods, taking into account the same object of interest. The comparative analysis was based on reference planes detected by Random Sample Consensus methodology in each cloud. By comparing the results of the different techniques, it was found for this case that three-dimensional reconstruction by stereo images estimated values closer to the real ones in comparison to those estimated by the structured light scanner, mainly due to the fact that, for three-dimensional reconstruction, the image acquisition was conducted statically.

The paper describes the results of ballistic tests of tungsten heavy alloys (WSC) susceptible to fragmentation. The materials being studied were the samples in the form of cal. 7.62 x 54 mm „Mosin” of heavy alloys projectiles prepared from the mixtures of powders W, Ni, Fe, and Co with the addition of ceramics. WSC’s were obtained from the compacts which were liquid phase or solid sintered in the hydrogen atmosphere. Final ballistics tests were conducted in accordance with the research procedure PBO-50. The results obtained allow for the graphic evaluation of WSC susceptibility to fragmentation. On the basis of analysis of the results obtained during ballistic experiment, the qualitative criterion of frangible WSC to fragmentation was proposed.

Copyright of Progress in Physics of Metals / Uspehi Fiziki Metallov is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U 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.)

The anti-ballistic properties of a new advanced composite armor system have been investigated with the aim to minimize the armor system total weight per unit area. The innovative protection, made of a silicon carbide ceramic outer layer and an inner composite back-packing layer formed by ultra-high molecular weight polyethylene (UHMWPE) fibers, namely Dyneema® Hard Ballistic 26, was realized and then tested performing dedicated ballistic impact tests. In order to investigate its permanent deformation, ceramic cracking, dimension of the rupture, and extension of the impact damage, nondestructive and destructive tests were conducted on the tested panels. The experimental results were used to develop and validate a transient nonlinear dynamic simulation model of the high-velocity impact of a 7.62 AP bullet on the tested armor system. After an accurate setting of the parameters involved in the description of the material constitutive models and of the involved physical phenomena, a complex numerical model was developed in the ANSYS-Autodyn® environment using both mesh and meshless approaches at the same time. The comparison reveals a good agreement between experimental and computational results in terms of ballistic properties, deformations, fragmentation, and fracture of the ballistic armor system. Hence, a new numerical model for the design and the optimization of the ballistic efficiency of composite armor systems was developed and can be now used in current practice. [ABSTRACT FROM AUTHOR]

An analytical model is developed to study the ballistic behavior of multilayer composite armors subjected to the high-velocity impact of projectiles with arbitrary angle of incidence, shape, size, and frictional characteristics. The thickness compaction resulting from the production process is also accounted for, quantifying the role of the curing pressure on the enhancement of the impact toughness of composite laminates. Finite element method simulations are used in a complementary manner to study damage and failure mechanisms within the targets. Both approaches are validated by extensive experimental ballistic tests on multilayer composite targets. The role of the layer stacking sequence is also investigated. It emerges that graded multilayer configurations yield higher toughness when the projectile penetrates plies with decreasing fracture strength. These results can explain common structural arrangements in biological armors as well as be exploited in the design and optimization of shielding structures against high-velocity projectiles. [ABSTRACT FROM AUTHOR]

Ballistic tests of hot-pressed panels of thickness 2.6-5.4 mm made of Dyneema (HB2 and HB80), aramid (Twaron No. 613 and Teksar), and basalt (TBK-100) woven fabrics were carried out. It is shown that the energy absorption efficiency of the panels based on Dyneema is by 30-75% higher than the other ones at the same suface density. For the panel based on Dyneema HB80, which showed the best results in ballistic tests, a low-parametric finite-element model to describe its interaction with a high-speed spherical striker is created. This model allows one to predict both the residual speed of the striker and the size of delamination zone with sufficient accuracy. [ABSTRACT FROM AUTHOR]

While many armies began to adopt large calibre weapons in the seventeenth and eighteenth century, frontier conflicts in the outer reaches of Europe and in North America have provided evidence for the retention of smaller calibres, particularly evidenced through the archaeological recovery of ammunition. Present within these assemblages are various forms of non-standard ammunition — i.e. not round — including bullets with casting sprues still attached at the time of firing. This paper provides an assessment of the combat effectiveness of these various types of ammunition through a series of firing tests using replicated ammunition. [ABSTRACT FROM PUBLISHER]

Results are presented from ballistic tests and studies of mosaic ceramic elements in the external layer of armor panels made by the French company 'ARES Protection SAS' with a level-IV protection rating. [ABSTRACT FROM AUTHOR]

• Presents the use of digitalization equipment in ballistic vest tests. • Features a performance analysis of a 3D scanner to measure trauma depths. • Spherical caps machined are digitized by a 3D scanner and by an arm measuring. • Trauma depths are obtained after Filtering and segmentation of the point clouds. • Measurement uncertainty is estimated and the methodology employed is validated. Considering the recent use of three-dimensional digitalization equipment in ballistic vest tests to characterize trauma caused by projectiles, this study carried out a performance analysis of a 3D structured light scanner to measure trauma depths. Artifacts were manufactured and digitized by a 3D scanner and by an articulated arm coordinate measuring machine, which provided the reference values. A process was developed for estimating the depth from the point clouds, one of the main contributions of this work. Filtering and segmentation of the point clouds allowed the extraction of the trauma depths for later comparison. The systematic errors reported in the literature for structured light scanning equipment were confirmed, and it was statistically verified that the critical trauma measurement values are correctly measured, with a bias of 0.11 mm and standard measurement uncertainty of 0.12 mm. Finally, a real ballistic vest test shows the applicability in a practical scenario. [ABSTRACT FROM AUTHOR]

Abstract: This paper focuses on ballistic tests of a new class of composite materials, i.e. hybrid nanocomposites. The two hybrid nanocomposites studied are fiber glass/epoxy/nanoclay and fiber glass/epoxy/nanographite. The fiber glass used is a plain weave 200 g/m2, while the nanoclay is an organically modified montmorillonite ceramic (Nanomer I30E). The expandable graphite used to generate the graphene nanosheets was from Graftech (grade 160-80N). Ballistic tests were performed considering two types of ammunition, i.e. 38 caliber and 9 mm full metal jacketed. The results showed that for a 38 revolver projectile a 5 mm thick nanocomposite with additional 5 mm nanoclay layer was able to absorb the energy efficiently. A 9 mm projectile, with speed of 380 m/s, was stopped by a two plates (5 mm each) arrangement with elastic deformation of the second plate less than 18 mm. The energies during the ballistic tests ranged from 316 to 576 J. [Copyright &y& Elsevier]

Abstract: In international peacekeeping operations, it is often necessary to send large amounts of equipment and personnel into highly unstable regions of the world. The troops will be particularly vulnerable in the time before and during the establishment of new camps. Therefore, it is important to get sufficient protection within a shortest possible period of time. As in most cases, long-distance transportation of the protective elements is required, and the weight of the system is thus a critical parameter. This paper presents the development of a new, cost-effective and lightweight protection concept for a 20 ft standard ISO container to be used as shelter in international operations. The work was carried out in six major steps. First, the many requirements for such protection systems were established. Then the basic concept idea, which in this study is an extruded aluminium panel filled with a granular material, was formulated. Next, the ballistic perforation resistance of both empty and mass-filled panels was determined experimentally for specified small-arms ammunition threats. In the next step, the panels were assembled to a protection wall and fixed to the container, and the global system was exposed to specified blast loadings using numerical simulations. Then, based on the many requirements and the findings from the experimental ballistic tests and numerical blast simulations, a design of a protection system for a 20 ft ISO container was proposed, before a prototype was constructed and built. Finally, the protection system was full-scale ballistic and blast tested under realistic conditions to validate the concept. In this paper, the steps associated with the design phase will be described, while the validation phase will be presented in an accompanying paper. [Copyright &y& Elsevier]

The capability of poly(ethylene-co-methacrylic acid) (E/MAA) to self-heal is well known, however, its mechanical properties are weak. In this study, composites with single and double layers of unidirectional (UD) carbon fibers were prepared by compression molding. Even a low mass fraction of fibers substantially improved the polymer. The flexural and tensile properties were tested at 0°, 45° and 90° fibers direction and compared to those of the matrix. The mechanical properties in the 0° direction proved superior. Flexural properties depended on the reinforcement distance from the stress neutral plane. The tensile modulus in the 0° direction was 13 times greater despite only a 2.5% mass fraction of fibers. However, both tensile modulus and strength were observed to degrade in the 90° direction. Dynamic mechanical analysis showed the dependence of both structure and properties on the thermal history of E/MAA. Tensile tests after ballistic impact showed that the modulus of the self-healed E/MAA was not affected, yet the strength, yield point, and particularly the elongation at break were reduced. A composite with higher fiber content could be prepared by mixing milled E/MAA particles in fibers prior to compression. [ABSTRACT FROM AUTHOR]

Several three-dimensional scanning methods have been developed and improved over the past 40 years. The peculiarities of each technique, associated with the computational advances of the period, allowed the increasing application and diffusion of the technology in several sectors, among them those related to metrology in ballistics and the testing of protective materials. The specific goal of such ballistic tests is to estimate the depth of indentation caused by projectiles. In particular, this study presents a comparative analysis between two three-dimensional optical scanning methods, taking into account the same object of interest. The comparative analysis was based on reference planes detected by Random Sample Consensus methodology in each cloud. By comparing the results of the different techniques, it was found for this case that three-dimensional reconstruction by stereo images estimated values closer to the real ones in comparison to those estimated by the structured light scanner, mainly due to the fact that, for three-dimensional reconstruction, the image acquisition was conducted statically. [ABSTRACT FROM AUTHOR]