Plasma Processes, LLC

Other

The United States of America As Represented by the Administrator of the

United States of America As Represented by the Administrator of Nasa

Timothy N McKechnie

Richard R Holmes

Chris A Power

Christopher A Power

Frank R Zimmerman

Robert M Saxelby

Scott O'Dell

Anatoliy Shchetkovskiy

Terry Tabor

Ronald L Daniel, Jr

George P Beason, Jr

Leo V M Antony

A structure which is resistant to corrosion at high temperatures comprises a layer of ruthenium and/or ruthenium alloy and a layer of a refractory metal having a high strength at high temperatures, such as rhenium. Further, the structure may include a layer of ceramic such as zirconia or hafnia on the exposed face of the ruthenium layer. Alternative embodiments of the present invention include a catalyst formed from a low strength support structure with a first metal layer and a second ruthenium catalytic layer on top of the first metal layer. Another alternative embodiment of the present invention includes the formation of high purity ruthenium electrodes that are resistant to corrosion at high temperatures.

High temperature corrosion resistant composite structure consisting of ruthenium and its alloys

Ultra fine and nanometer powders and a method of producing same are provided, preferably refractory metal and ceramic nanopowders. When certain precursors are injected into the plasma flame in a reactor chamber, the materials are heated, melted and vaporized and the chemical reaction is induced in the vapor phase. The vapor phase is quenched rapidly to solid phase to yield the ultra pure, ultra fine and nano product. With this technique, powders have been made 20 nanometers in size in a system capable of a bulk production rate of more than 10 lbs/hr. The process is particularly applicable to tungsten, molybdenum, rhenium, tungsten carbide, molybdenum carbide and other related materials.

Nano powders, components and coatings by plasma technique

A coating with the ability to protect (1) the inside wall (i.e., lining) of a rocket engine combustion chamber and (2) parts of other apparatuses that utilize or are exposed to combustive or high-temperature environments. The novelty of this invention lies in the manner a protective coating is embedded into the lining.

Rocket combustion chamber coating

A high temperature and highly corrosive resistant structure and method of fabricating the structure. In one embodiment of the present invention, vacuum plasma spray or other materials deposition techniques are used to fabricate the structure on a removable support member in the form of a gradient or composite structure that sequentially consists of a 100% ceramic interior layer, a first transition layer of ceramic/refractory metal, a layer of 100% refractory metal, a second transition layer of ceramic/refractory metal, and an outer layer of 100% ceramic material. In a second embodiment, the ceramic/refractory metal/ceramic cartridge is formed without transition layers between the ceramic and metal layers. In another embodiment of the invention the structure is fabricated on a removable support member by depositing an outer layer of ceramic material on a refractory metal. No transition layers of ceramic material/refractory metals are used. In a further embodiment of the present invention, the structure is fabricated on a removable support member by vacuum plasma spraying only a refractory metal on the removable support member which has a layer of a corrosion/oxidation preventative coating thereon which has been applied to the support member by vacuum plasma spraying or other material deposition technique.

High temperature and highly corrosive resistant sample containment

An improved nozzle for reducing overspray in high temperature supersonic plasma spray devices comprises a body defining an internal passageway having an upstream end and a downstream end through which a selected plasma gas is directed. The nozzle passageway has a generally converging/diverging Laval shape with its upstream end converging to a throat section and its downstream end diverging from the throat section. The upstream end of the passageway is configured to accommodate a high current cathode for producing an electrical arc in the passageway to heat and ionize the gas flow to plasma form as it moves along the passageway. The downstream end of the nozzle is uniquely configured through the methodology of this invention to have a contoured bell-shape that diverges from the throat to the exit of the nozzle. Coating material in powder form is injected into the plasma flow in the region of the bell-shaped downstream end of the nozzle and the powder particles become entrained in the flow. The unique bell shape of the nozzle downstream end produces a plasma spray that is ideally expanded at the nozzle exit and thus virtually free of shock phenomena, and that is highly collimated so as to exhibit significantly reduced fanning and diffusion between the nozzle and the target. The overall result is a significant reduction in the amount of material escaping from the plasma stream in the form of overspray and a corresponding improvement in the cost of the coating operation and in the quality and integrity of the coating itself.

Plasma spray nozzle with low overspray and collimated flow

A process for making a combustion chamber for a rocket engine wherein a copper alloy in particle form is injected into a stream of heated carrier gas in plasma form which is then projected onto the inner surface of a hollow metal jacket having the configuration of a rocket engine combustion chamber. The particles are in the plasma stream for a sufficient length of time to heat the particles to a temperature such that the particles will flatten and adhere to previously deposited particles but will not spatter or vaporize. After a layer is formed, cooling channels are cut in the layer, than the channels are filled with a temporary filler and another layer of particles is deposited.

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Huntsville, AL, United States of America

Timothy N McKechnie