Antiballistic armour plate includes a ceramic body including a hard material, provided, on its inner face, with a back energy-dissipating coating. The ceramic body is monolithic. The constituent material of the ceramic body includes grains of ceramic material having a Vickers hardness that is higher than 15 GPa, and a matrix binding the grains, the matrix including a silicon nitride phase and/or a silicon oxynitride phase, the matrix representing between 5 and 40% by weight of the constituent material of the ceramic body. The maximum equivalent diameter of the grains of ceramic material is smaller than or equal to 800 micrometres. The constituent material of the ceramic body has an open porosity that is higher than 5% and lower than 14%. The metallic silicon content in the material, expressed per mm of thickness of the body, is lower than 0.5% by weight.

A blast resistant container includes a rigid outer cylinder, a rigid inner cylinder and at least one pumice brick. The rigid inner cylinder has a longitudinal axis. The at least one pumice brick is within the interior of the rigid inner cylinder.

The disclosure relates to sintered ceramic grains comprising 3-55 wt. % alumina, 40-95 wt. % zirconia and 1-30 wt. % of one or more other inorganic components. The invention further relates to a method for preparing ceramic grains according to the invention, comprising: making a slurry comprising alumina, zirconia; making droplets of the slurry; introducing the droplets in a liquid gelling-reaction medium wherein the droplets are gellified; drying the gellified deformed droplets.

A compact antenna for centimetric frequency bands includes an active planar element forming a radiator, coupled to an input of a receiver circuit and/or to the output of an emitter circuit, and a passive planar element forming a reflector. The passive planar element is formed by a periodic structure of the metamaterial type comprising a network of resonating cells, in particular cells of the complementary concentric slit-ring type Complementary Split-Ring Resonator (CSRR). A clip-shaped support made of a dielectric material supports the active planar element and the passive planar element.

Disclosed herein are embodiments of a releasably engagable system of ballistic-resistant panels including a first ballistic-resistant panel comprising a ceramic plate system, the first ballistic-resistant panel having opposing first ballistic-resistant panel front and back surfaces; and a second ballistic-resistant panel having opposing second ballistic-resistant panel front and back surfaces. Additionally, the embodiments of the releasably engagable systems of ballistic-resistant panels include at least one of fasteners, an adhesive coating, or a securement element, all of which function to releasably engage the second ballistic-resistant panel front surface with the first ballistic-resistant panel back surface in fixed adjacent relation to provide releasably engaged ballistic-resistant panels.

An armor plate system includes an integrated damage detector which may permit field testing of an armor plate. The system includes a ceramic plate and a piezoelectric transducer attached to lateral face of the ceramic plate. The piezoelectric transducer may apply a signal to the ceramic plate and receive a reflected signal. The applied signal may form a compression wave. An ultrasonic signal may be applied.

An armor system with a composite laminate having at least four alternating layers (two bi-layers) of a first material and a second material, the first material having a lower acoustic impedance than the second material. The first material is an elastomer and the second material can be a hard material such as steel, aluminum, or ceramic, or an elastomer with a higher acoustic impedance than the first material. The laminate can include many alternating layers of the first and second materials, and can be adhered or affixed to a thicker armor substrate. Additional protective elements such as corrugated metal-ceramic panels and armored glass cylinders can be added to improve resistance to armor piercing rounds, explosively formed penetrators, or other threats.

An armor system that includes a first armor article that includes a plurality of energy-dispersion objects arranged in a predetermined configuration, wherein the plurality of energy-dispersion objects includes a plurality of hollow objects, and wherein at least some of the plurality of hollow objects are filled with an inner filler material; and a lock mechanism configured to hold the plurality of energy-dispersion objects in the predetermined configuration. A method for manufacturing an armor system, the armor system including a first armor article, the method including producing a plurality of hollow hemispheres; affixing pairs of the plurality of hemispheres to one another to form a first plurality of spheres; treating each one of the plurality of hemispheres with an anti-ballistic treatment; inserting a filler material into each one of the plurality of hemispheres; and locking the first plurality of spheres into a predetermined configuration.

Inventive manufacture of CrB.sub.2—Al.sub.2O.sub.3 composites is based on pressureless sintering. According to typical inventive practice, CrB.sub.2 powder and Al.sub.2O.sub.3 powder are mixed together in selected volumetric proportions so that the volume of the CrB.sub.2 does not exceed 50% of the overall volume of the CrB.sub.2—Al.sub.2O.sub.3 mixture. The CrB.sub.2—Al.sub.2O.sub.3 mixture is shaped into a green body. The green body is pressureless sintered in a non-oxidizing atmosphere at a firing temperature in the approximate range between 1600° C. and 2050° C. The present invention succeeds in preparing, via pressureless sintering, a proportionality-associated range of compositions in the CrB.sub.2—Al.sub.2O.sub.3 system, which is a potentially “advanced” ceramic system. A typical inventively fabricated CrB.sub.2—Al.sub.2O.sub.3 composite is inventively configured in a complex shape, and has “advanced” material (e.g., mechanical) properties that are favorable for a contemplated application. Inventive manufacture of ceramic-ceramic composites is thus dually attributed, and uncommonly so, with complex shape-ability and advanced capability.

A measurement system may include control electronics; an electrical signal source; a plurality of measurement system electrical contacts; at least one feature for repeatably electrically connecting the plurality of measurement system electrical contacts to selected locations of a tested material. The control electronics may be configured to cause the electrical signal source to output an electrical signal; determine a measured voltage in response to the electrical signal using a measurement electrical contact from the plurality of measurement system electrical contacts. The measurement electrical contact is electrically coupled to the tested material. The control electronics also may be configured to determine whether the tested material includes a crack or other defect based on the measured voltage.