The Johns Hopkins University

Reactive Nanotechnologies, Inc.

Nanofoil Corporation

Indium Corporation of America

Omar Knio

Timothy P Weihs

David Van Heerden

Timothy Ryan Rude

Michael Reiss

Jesse E Newson

Michael V Brown

Alan Duckham

Jai S Subramanian

Ellen Heian

Todd Hufnagel

Dale Deger

Etienne Besnoin

Ronald L Spraker

Howard S Feldmesser

Ramzi Vincent

Yuping Lin

Somasundaram Valliappan

Albert Joseph Swiston, Jr

Jiaping Wang

Ellen M Heian

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.

Reactive composite material structures with electrostatic discharge protection and applications thereof

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.

Method for fabricating large dimension bonds using reactive multilayer joining

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.

Methods and device for controlling pressure in reactive multilayer joining and resulting product

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. It is expected that the reactive joints may also have better fatigue properties compared with conventional furnace joints.

Nanostructured soldered or brazed joints made with reactive multilayer foils

Embodiments of the invention include a method for sealing a container. The method includes, providing at least two components of the container, positioning a crushable material between the at least two components, positioning a reactive multilayer material between the at least two components, deforming the crushable material so as to form a seal between the at least two components, chemically transforming the reactive multilayer material so as to join the at least two components.

Hermetically sealing a container with crushable material and reactive multilayer material

Container hermetically sealed with crushable material and reactive multilayer material

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 layers, 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 or soften the joining material, which upon cooling will form a strong bond, joining two or more bulk materials. If no joining material is used, the foil reaction supplies heat directly to at least two bulk materials, melting or softening a portion of each bulk, which upon cooling, form a strong bond. Additionally, the foil may be designed with openings that allow extrusion of the joining (or bulk) material through the foil to enhance bonding.

Methods of making and using freestanding reactive multilayer foils

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 layers, 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.

Reactive multilayer foil with conductive and nonconductive final products

Composite reactive multilayer foil

Freestanding reactive multilayer foils

Growing community of inventors

Timonium, MD, United States of America

Omar Knio