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Gash, Alexander E.

Publications and source records attributed to Gash, Alexander E..

13 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Multifunctional reactive inks, methods of use and manufacture thereof

In one embodiment, a method includes dispersing a plurality of particles in solution to form a dispersion and adding a stabilizing agent to the dispersion in an amount sufficient to cause the dispersion to exhibit one or more predetermined rheological properties. The particles in the dispersion are configured to complete a self-propagating and/or self-sustaining reaction upon initiation thereof. In another embodiment, a method includes depositing a material on a substrate. The material includes: a plurality of particles configured to complete a self-propagating and/or self-sustaining reaction upon initiation thereof, a solvent system, and one or more stabilizing agents.

Sullivan, Kyle T.↗
DOE OSTI2021

Additive manufacturing of multi-component parts for customizable energetic systems

An apparatus, system, and method utilizes at least two separate components during the process of producing the final product. At least one component during the process is produced using additive manufacturing, and additional components are components that are combined with the additively manufactured part. The apparatus, system, and method includes at least one energetic component and at least one second inert component. An additive manufacturing system produces a scaffold of said first energetic component(s). A system adds the second component(s) to the scaffold to produce the energetic material product.

Sullivan, Kyle T.↗
DOE OSTI2019

Fast Magic-Angle Spinning Solid-State 1 H NMR Reveals Structural Relationships in the High Explosive 2,6-Diamino-3,5-dinitropyrazine-1-oxide (LLM-105)

1 H nuclear magnetic resonance (NMR) experiments were performed on the proposed insensitive high-explosive 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) at high-speed magic-angle spinning rates of up to 60 kHz. Here, these rapid speeds produce well-resolved spectra that aid in the study of the chemical and structural properties of this material. Extraordinarily long 1 H T 1 values were observed for the main amine peaks from the LLM-105 explosive and can be used to differentiate between peaks from the main compound and those of impurities. Further, advanced NMR measurements and simulations reveal unique spectral properties due to the strong network of intramolecular and intermolecular hydrogen bonding and provide insights in the structure of LLM-105.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Multifunctional reactive inks, methods of use and manufacture thereof

In one embodiment, a material includes a plurality of particles, a solvent system and one or more stabilizing agents; the particles are configured to complete a self-propagating and/or self-sustaining reaction upon initiation thereof. In another embodiment, a method includes dispersing a plurality of particles in solution to form a dispersion and adding a stabilizing agent to the dispersion in an amount sufficient to cause the dispersion to exhibit one or more predetermined rheological properties; again, the particles in the dispersion are configured to complete a self-propagating and/or self-sustaining reaction upon initiation thereof. In still another embodiment, a method includes depositing a material on a substrate; the material includes a plurality of particles configured to complete a self-propagating and/or self-sustaining reaction upon initiation thereof, a solvent system and one or more stabilizing agents.

Sullivan, Kyle↗
DOE OSTI2019

Methods and systems for electrophoretic deposition of energetic materials and compositions thereof

A method includes providing a plurality of particles of an energetic material suspended in a dispersion liquid to an EPD chamber or configuration; applying a voltage difference across a first pair of electrodes to generate a first electric field in the EPD chamber; and depositing at least some of the particles of the energetic material on at least one surface of a substrate, the substrate being one of the electrodes or being coupled to one of the electrodes.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Active Mixing of Reactive Materials for 3D Printing

The mixing of materials during additive manufacturing is a major benefit which allows one to compositionally and spatially tailor material properties, for example to locally control the reactivity in fuel–oxidizer systems known as thermites. This work characterizes an active mixing printhead used in conjunction with a 3D printing process known as Direct Ink Writing. Besides compositional control, a major benefit of this approach is that it offers a safe method for working with these materials, which can otherwise be hazardous once mixed. Custom fuel and oxidizer inks are fed at fixed volumetric rates into an active mixing printhead, and both the rotational speed of the mixing impeller as well as the fuel–oxidizer ratio are varied. Upon ignition, the propagation speed increases with the rotational speed of the mixer and plateaus above a critical value of ≈750 rpm. The critical mixing speed is corroborated by computational fluid simulations and an analytical expression that considers the inks’ complex fluid behavior. Additionally, varying the composition results in a wide range of propagation speeds with peak reactivity corresponding to a fuel–rich formulation ( Φ = 1.5). As a result, a test article incorporating a fast– and slow–burning region demonstrates how spatial composition can manipulate the reactivity.

3D printing↗
DOE OSTI2018

Development and Characterization of 3D Printable Thermite Component Materials

Additive manufacturing (AM) has recently shown great promise as a means to tailor a wide range of material properties, both quasi-static and dynamic. An example of controlling the dynamic behavior is to tailor the chemical energy release rate in composite energetic materials such as thermites – which are a subset of pyrotechnics that use a metal fuel and a metal oxide as an oxidizer. Since these materials are most hazardous once finely mixed, the approach taken here is to formulate the fuel and oxidizer separately such that they can be mixed on-the-fly. The development, formulation, and characterization of two respective aqueous 3D printable inks consisting of Al and CuO are discussed. The rheological properties and ability of the material to span gaps are characterized. To demonstrate that the materials could be mixed and sustain a reaction, the inks are fed into a static mixing nozzle and extruded into a high-aspect ratio test strip. Upon drying, the material can be ignited and sustain a propagation through the part. These results present a facile, and safe, way to AM thermite which can be used for more detailed follow on studies looking at the role of architecture on the reactivity.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Architected materials and structures to control shock output characteristics

A system that provides control of the output shockwave properties of energetic material wherein the system includes an energetic material having a first portion and a second portion. An additive manufacturing system combines the first portion and the second portion of the energetic material wherein the first portion and the second portion are positioned relative to each other to provide control of the output shockwave properties of the energetic material.

36 MATERIALS SCIENCE↗
DOE OSTI2018

High temperature oxygen treated carbon aerogels

Disclosed here is a method for increasing the hydrophilicity of a carbon aerogel, comprising heating the carbon aerogels under air or a gas having a higher concentration of oxygen than air at a temperature of about 200.degree.-500.degree. C. to obtain an activated carbon aerogel. Also disclosed include an activated carbon aerogel obtained by the method, an electrode comprising the activated carbon aerogel, and a supercapacitor or capacitive deionization device comprising the electrode.

Stadermann, Michael↗
DOE OSTI2018

K-9 training aids made using additive manufacturing

Additive Manufacturing (AM) is used to make aids that target the training of K-9s to detect explosives. The process uses mixtures of explosives and matrices commonly used in AM. The explosives are formulated into a mixture with the matrix and printed using AM techniques and equipment. The explosive concentrations are kept less than 10% by wt. of the mixture to conform to requirements of shipping and handling.

42 ENGINEERING↗
DOE OSTI2018

Explosives mimic for testing, training, and monitoring

Additive Manufacturing (AM) is used to make mimics for explosives. The process uses mixtures of explosives and matrices commonly used in AM. The explosives are formulated into a mixture with the matrix and printed using AM techniques and equipment. The explosive concentrations are kept less than 10% by wt. of the mixture to conform to requirements of shipping and handling.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Controlling Material Reactivity Using Architecture

3D-printing methods are used to generate reactive material architectures. We observed several geometric parameters in order to influence the resultant flame propagation velocity, indicating that the architecture can be utilized to control reactivity. Two different architectures, channels and hurdles, are generated, and thin films of thermite are deposited onto the surface. Additionally, the architecture offers a route to control, at will, the energy release rate in reactive composite materials.

36 MATERIALS SCIENCE↗