Abstract: A method of producing a reactive powder includes providing a bulk structure of reactive material comprising a first reactant and a second reactant, the bulk structure having a preselected average spacing between the first and the second reactants; and mechanically processing the bulk structure of reactive material to produce a plurality of particles from the bulk structure such that each of the plurality of particles comprises the first and second reactants having an average spacing that is substantially equal to the preselected average spacing of the bulk structure of reactive material. The first and second materials of the plurality of particles react with each other in an exothermic reaction upon being exposed to a threshold energy to initiate the exothermic reaction and remain substantially stable without reacting with each other prior to being exposed to the threshold energy.

Abstract: An embodiment in accordance with the present invention provides a method for creating and consolidating fragments and a useable structure formed from said consolidated fragments. The method includes swaging a metal powder into a first consolidated structure. The consolidated structure is ground to form particles and the particles are sifted to select those with a predetermined diameter. The particles having the predetermined diameter can then be swaged into a second consolidated structure. The resultant second consolidated structure is therefore configured to fragment controllably. The second consolidated structure can also be formed from reactive metal laminates such that the structure also has chemical energy.

Abstract: An energetic composite having a plurality of reactive particles each having a reactive multilayer construction formed by successively depositing reactive layers on a rod-shaped substrate having a longitudinal axis, dividing the reactive-layer-deposited rod-shaped substrate into a plurality of substantially uniform longitudinal segments, and removing the rod-shaped substrate from the longitudinal segments, so that the reactive particles have a controlled, substantially uniform, cylindrically curved or otherwise rod-contoured geometry which facilitates handling and improves its packing fraction, while the reactant multilayer construction controls the stability, reactivity and energy density of the energetic composite.

Abstract: An energetic composite having a plurality of reactive particles each having a reactive multilayer construction formed by successively depositing reactive layers on a rod-shaped substrate having a longitudinal axis, dividing the reactive-layer-deposited rod-shaped substrate into a plurality of substantially uniform longitudinal segments, and removing the rod-shaped substrate from the longitudinal segments, so that the reactive particles have a controlled, substantially uniform, cylindrically curved or otherwise rod-contoured geometry which facilitates handling and improves its packing fraction, while the reactant multilayer construction controls the stability, reactivity and energy density of the energetic composite.

Abstract: Applicants have discovered that electrostatic discharge (ESD) may, in some circumstances, result in current densities sufficient to ignite unprotected reactive composite materials. They have further discovered that a reactive composite material (RCM) can be protected from ESD ignition without adversely affecting the desirable properties of the RCM by the application of conducting and/or insulating materials at appropriate locations on the RCM. Thus ESD-protected RCM structures can be designed for such sensitive applications as ignition of propellants, generation of light bursts, and structural materials for equipment that may require controlled self-destruction.

Abstract: A method of producing a reactive powder includes providing a bulk structure of reactive material comprising a first reactant and a second reactant, the bulk structure having a preselected average spacing between the first and the second reactants; and mechanically processing the bulk structure of reactive material to produce a plurality of particles from the bulk structure such that each of the plurality of particles comprises the first and second reactants having an average spacing that is substantially equal to the preselected average spacing of the bulk structure of reactive material. The first and second materials of the plurality of particles react with each other in an exothermic reaction upon being exposed to a threshold energy to initiate the exothermic reaction and remain substantially stable without reacting with each other prior to being exposed to the threshold energy.

Abstract: Applicants have discovered that electrostatic discharge (ESD) may, in some circumstances, result in current densities sufficient to ignite unprotected reactive composite materials. They have further discovered that a reactive composite material (RCM) can be protected from ESD ignition without adversely affecting the desirable properties of the RCM by the application of conducting and/or insulating materials at appropriate locations on the RCM. Thus ESD-protected RCM structures can be designed for such sensitive applications as ignition of propellants, generation of light bursts, and structural materials for equipment that may require controlled self-destruction.

Abstract: In accordance with the invention, containers or interfaces having two surfaces 201a and 201b to be joined, and a region to be sealed, are fused by providing between the surfaces 201a and 201b a thin strip or wire of RCM 102 embedded within a fusible material 101, applying pressure 205 and igniting the RCM 102. The released energy from the ignited RCM 102 results in a melting of the fusible material 101 and subsequent bonding of the fusible material 101 upon cooling to the 101 surrounding surfaces 201a and 201b, achieving a hermetic seal there between without the use of a separate gasket component.

Abstract: Applicants have discovered new composite materials and have developed a variety of new ways of making reactive composite materials (RCMs) and methods of controlling the properties and characteristics of the materials that are pertinent to numerous new or improved applications. This patent application is directed to new and improved ways of making reactive composite materials using mechanical deformation and making such materials with controlled, predictable characteristics. This application is also directed toward useful applications of the resulting materials. In accordance with the invention, RCMs are fabricated by a series of mechanical deformation steps. In the first deformation step, an assembly of reactive layers and/or particles is plastically deformed to reduce its cross sectional area by one-half or more. This severe initial deformation substantially eliminates the tendency of deformed layers to delaminate and eliminates the necessity of using specially cleaned metal layers.

Abstract: A method for bonding a concentrating photovoltaic receiver module to a heat sink using a reactive multilayer foil as a local heat source, together with layers of solder, to provide a high thermal conductivity interface with long term reliability and ease of assembly.

Abstract: A process and apparatus for the reactive multilayer joining of components utilizing a print screen metallization technique to bond difficult-to-wet materials and temperature sensitive materials to produce joined products.

Abstract: Novel reactive composite materials and associated methods for making the same which are pertinent to numerous new or improved applications. The method for making the reactive composite materials utilizes mechanical deformation to manufacture such materials with controlled, predictable characteristics. In the first deformation step, an assembly of reactive layers and/or particles is plastically deformed to reduce its cross sectional area by one-half or more. Portions of the deformed sheets are stacked or bent into a new assembly, and the new assembly is then deformed. The steps of assembly and deformation are repeated a sufficient number of times that the resulting materials are only locally layered but have relatively uniform reaction velocity and heat generating characteristics predictable by stochastic models derived herein.

Abstract: A method for joining component bodies of material over bonding regions of large dimensions by disposing a plurality of substantially contiguous sheets of reactive composite materials between the bodies and adjacent sheets of fusible material. The contiguous sheets of the reactive composite material are operatively connected by an ignitable bridging material so that an igniting reaction in one sheet will cause an igniting reaction in the other. An application of uniform pressure and an ignition of one or more of the contiguous sheets of reactive composite material causes an exothermic thermal reaction to propagate through the bonding region, fusing any adjacent sheets of fusible material and forming a bond between the component bodies.

Abstract: A device and method for emitting electromagnetic radiation utilizing a reactive composite material (RCM) as an emission source. By selective modification of the reactive composite material (RCM), attributes of the emitting device, including the ability to produce specific radiation intensity levels at specific electromagnetic wavelengths, the ability to emit for a specific duration, the avoidance of dangerous reaction products, portability, geometric design flexibility, and simple, safe storage may be selected.

Abstract: The invention includes a method of joining two components. The method includes providing at least two components to be joined, a reactive multilayer foil, and a compliant element, placing the reactive multilayer foil between the at least two components, applying pressure on the two components in contact with the reactive multilayer foil via a compliant element, and initiating a chemical transformation of the reactive multilayer foil so as to physically join the at least two components. The invention also includes two components joined using the aforementioned method.

Abstract: Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining lawyers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g. air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt the joining materials, which upon cooling will form a strong bond, joining two or more bulk materials.

Abstract: A method for bonding components with a reactive multilayer foil, wherein during bonding, the components are held at a temperature or temperature gradient chosen to reduce thermal stress in the resulting bonded product.

Abstract: The invention includes a method of joining two components. The method includes providing at least two components to be joined, a reactive multilayer foil, and a compliant element, placing the reactive multilayer foil between the at least two components, applying pressure on the two components in contact with the reactive multilayer foil via a compliant element, and initiating a chemical transformation of the reactive multilayer foil so as to physically join the at least two components. The invention also includes two components joined using the aforementioned method.

Abstract: A reactive composite structure having selected energetic and mechanical properties, and methods of making reactive composite structures enabling the construction of complex parts and components by machining and forming of reactive composite materials without compromising the energetic or mechanical properties of the resulting reactive composite structure.

Abstract: Self-propagating formation reactions in nanostructured multilayer foils provide rapid bursts of heat at room temperature and therefore can act as local heat sources to melt solder or braze layers and join materials. This reactive joining method provides very localized heating to the components and rapid cooling across the joint. The rapid cooling results in a very fine microstructure of the solder or braze material. The scale of the fine microstructure of the solder or braze material is dependant on cooling rate of the reactive joints which varies with geometries and properties of the foils and components. The microstructure of the solder or braze layer of the joints formed by melting solder in a furnace is much coarser due to the slow cooling rate. Reactive joints with finer solder or braze microstructure show higher shear strength compared with those made by conventional furnace joining with much coarser solder or braze microstructure.