A dual hardness steel article comprises a first air hardenable steel alloy having a first hardness metallurgically bonded to a second air hardenable steel alloy having a second hardness. A method of manufacturing a dual hard steel article comprises providing a first air hardenable steel alloy part comprising a first mating surface and having a first part hardness, and providing a second air hardenable steel alloy part comprising a second mating surface and having a second part hardness. The first air hardenable steel alloy part is metallurgically secured to the second air hardenable steel alloy part to form a metallurgically secured assembly, and the metallurgically secured assembly is hot rolled to provide a metallurgical bond between the first mating surface and the second mating surface.

A ballistic resistant armor plate assembly includes an armor plate which includes a strike side and a back side and a solid foam material positioned in overlying relationship with respect to the strike side and the back side of the armor plate.

In one general aspect, an armor panel includes a first layer, a second layer, and a third layer. The first layer having a first thickness (T1). The second layer is coupled to the first layer and has a second thickness (T2). The second layer includes one of the following materials steel, cermet, cemented carbide, a metal matrix composite, or a combination thereof. The third layer is coupled to the second layer and has a third thickness (T3). The third layer includes an ultra-high molecular weight polyethylene (UHMWPE) composite or syntactic foam.

A dual hardness steel article comprises a first air hardenable steel alloy having a first hardness metallurgically bonded to a second air hardenable steel alloy having a second hardness. A method of manufacturing a dual hard steel article comprises providing a first air hardenable steel alloy part comprising a first mating surface and having a first part hardness, and providing a second air hardenable steel alloy part comprising a second mating surface and having a second part hardness. The first air hardenable steel alloy part is metallurgically secured to the second air hardenable steel alloy part to form a metallurgically secured assembly, and the metallurgically secured assembly is hot rolled to provide a metallurgical bond between the first mating surface and the second mating surface.

A device for protecting a mobile or static structure against the blast from an explosion or detonation and associated projections of material. The device includes a protective casing made of several materials, the protective casing being located at a distance from the structure to be protected and connected to the structure by an elastomer connection. The protective casing is elastically deformable so as to be able to deform elastically for the duration of the stress by oscillating to spread the energy of the blast from the explosion over its surface and over time in several directions, and then to return completely or partially to its original shape after a period of time.

A bulletproof steel plate with a tensile strength of 2000 MPa grade and a Brinell Hardness of 600 grade and a manufacturing method thereof, characterized by that the chemical elements in mass percentage thereof being: 0.35-0.45% of C, 0.80-1.60% of Si, 0.3-1.0% of Mn, 0.02-0.06% of Al, 0.3-1.2% of Ni, 0.30-1.00% of Cr, 0.20-0.80% of Mo, 0.20-0.60% of Cu, 0.01-0.05% of Ti, 0.001-0.003% of B, and the balance being Fe and inevitable impurities. The tensile strength of the steel plate can reach a grade of 2000 MPa and its Brinell Hardness can reach a grade of 600.

Boron nitride nanotubes (BNNTs), boron nitride nanoparticles (BNNPs), carbon nontubes (CNTs), graphites, or their combinations, are incorporated into matrices of polymer, ceramic or metals. Fibers, yarns, and woven or nonwoven mates of BNNTs are uses as toughening layers in penetration resistant materials to maximize energy absorption and/or high hardness layers to rebound or deform penetrators. They can be also uses as reinforcing inclusions combining with other polymer matrices to create composite layer like typical reinforcing fibers such as Kevlar, Spectra, ceramics and metals. Enhanced wear resistance and prolonged usage time, even under harsh conditions, are achieved by adding boron nitride nanomaterials because both hardness and toughness are increased. Such materials can be used in high temperature environments since the oxidation temperature of BNNTs exceeds 800 C. in air. Boron nitride based composite materials are useful as strong structural materials for anti-micrometeorite layers for spacecraft and space suits, ultra strong tethers, protective gear for the human body as well as for vehicles, helmets, shields and safety suits/helmets for industry.

A protective wall for use in a structure such as a ship comprises a first and second metal layer, with an armor plate in between and layers of elastomeric material between the armor plate and the first and second metal layer respectively. The first and second metal layer having a higher ductility than the armor plate, the armor plate being mounted between the first and second metal layer in a way that allows the first and second metal layers to stretch relative to armor steel plate at least in response to forces resulting from impact by fragments from an explosion. When an explosion occurs in a space bounded by the protective wall, the first and second metal layer deflect under the pressure pulses due to blasts, stretching relative to the armor plate. The armor plate blocks high speed fragments. The elastomeric material has a double function: it increases the resistance of the armor plate to fragments and it allows for separation of the armor plate from the first and second metal layer, allowing them to stretch.

Structures based upon periodic cellular materials that provide a potential for defeating combinations of both air blast loading and ballistic attack either sequentially or simultaneously, or combination of both. The cellular structures may also be configured to meet the stiffness and strength support requirements of particular vehicle or other applications, systems or structures. The armor is therefore potentially able to support normal service loads and defeat blast and ballistic threats when necessary. The structure provides for using efficient load support capabilities of the material (without a high armor protection level) in low threat conditions, as well as the ability to modify the system to increase its level protection to a desired or required level. This would reduce the weight of the protection system in normal (low threat) conditions which reduces vehicle wear and tear, as well as cost savings in fabrication of applicable structures or systems.

An electric reactive armor (10) comprises a first electrode (1) and a second electrode (2) spaced apart from the first electrode, to which electrodes (1, 2) a high voltage can be applied so as to disrupt a charge contacting the electrodes. The second electrode (2) comprises an electrically conductive structure (21) having a plurality of surfaces (22) embedded in an insulating material (23), such that the charge jet penetrates successive surfaces of the electrically conductive structure. The electrically conductive structure (21) comprises a meandering structure and/or a structure of linked cavities, such as a honeycomb structure.