Thiokol Corporation

Cordant Technologies Inc.

US Government As Represented by the Secretary of the Army

Morton Thiokol Inc.

Larry W Poulter

Russell A Crook

Ronald W Nelson

Robert B Smalley, Jr

Marvin C Hawkins

Michael L Levinthal

Wendell N Christensen

James W Sinclair

Merylin B Lovett

Kenneth J Schulte

Elizabeth K Bonderson

David M Cannon

Gale F Allred

Ernest D Brown

John L Brown

William F Dunn

The present invention concerns an erosion resistant, low signature liner for solid propellant rocket motors and rocket motors having such a low signature liner. The liner combustion products in the exhaust plume have low visibility in the IR and visible light spectra which is essential for use in low signature solid propellant rocket motors. The liner also forms an in-situ protective layer at elevated temperatures for enhanced erosion resistance. These erosion resistant properties eliminate the need for supplemental case insulation which would contribute additional smoke and combustion products to the exhaust plume as well as add additional costs and inert weight to the motor.

Erosion resistant-low signature liner for solid propellant rocket motors

An assembly mating first and second tubular bodies is disclosed. The mating assembly includes at least a sleeve structure forming a part of the first tubular body and defining an inner receptacle surface region, a compression loading assembly integrally formed with, constituted by, or otherwise securable to the second tubular body and at least partially received in the sleeve structure, and a cured adhesive bond positioned between an exterior surface region of the compression loading assembly and the inner receptacle surface region to couple the sleeve structure to the compression loading assembly. The compression loading assembly is laterally expandable at at least the exterior surface region thereof and constructed and arranged relative to the cured adhesive bond so that expansion of the exterior surface region compressively loads the cured adhesive bond in a substantially lateral direction. The strength of the adhesive bond is thereby increased against shear stresses acting on said mating assembly due to longitudinal and/or torsional loading.

Assembly including tubular bodies and mated with a compression loaded

A robust polyurethane liner is disclosed for solid propellant rocket motors which is insensitive to large variations in stoichiometry, exhibits increased cohesive strength and, when used in combination with a unique two coat (wet coat) liner process described below, modifies the ballistic properties of the adjacent interfacial propellant layer. The liner compositions include a polymeric binder having a plurality of reactive hydroxyl functional groups and a curing agent having a plurality of reactive isocyanate functional groups. The quantity of binder and curing agent is selected such that the NCO/OH ratio is in the range from 1.5 to 4.5. Diisocyanate curing agents are particularly useful. A bonding agent, such as a polyfunctional aziridine compound, is typically present in the liner composition in an amount ranging from about 3% to about 5%, by weight. An oligomer catalyst is included in the liner composition in an amount ranging from about 15% to about 50%, by weight. Diammonium phosphate ((NH.sub.4).sub.2 HPO.sub.4) functions as an oligomer catalyst and as a ballistic modifier to inhibit propellant burn rate when the liner is cured concurrently with the propellant. A colorant, such as rhodamine B, may optionally be included to assist in determining coverage or thickness of the liner coating.

Robust propellant liner and interfacial propellant burn rate control

A surface preparation process has been developed for titanium and titanium alloy substrates that greatly improves the resulting bond. The process improves bond strength, fracture toughness, durability and failure mode of adhesive bonds. The process also decreases the sensitivity of titanium substrates to processing variables such as humidity, temperature and hence the processing timelines. The process involves treating a titanium or titanium alloy surface with a soluble silicate solution, such as an alkali metal metasilicate, and subsequently treating the surface with a solution of an organofunctional silane. Employing this two step process, bonding to the titanium substrate is improved.

Method of surface preparation of titanium substrates

A surface preparation process has been developed for aluminum and aluminum alloy substrates that greatly improves the resulting bond. The process improves bond strength, fracture toughness, durability and failure mode of adhesive bonds. The process also decreases the sensitivity of aluminum substrates to processing variables such as humidity, temperature and hence the processing timelines. The process involves treating an aluminum surface with a solution of an alkali metal metasilicate, and subsequently treating the surface with a solution of an organofunctional silane. Employing this two step process, bonding to the aluminum substrate is improved.

Method of surface preparation of aluminum substrates

Tooling for solid propellant casting consisting essentially of a shaped, filled polymer or copolymer article having an outer layer of cured polyvinyl butyral. The casting tooling is used extensively throughout the solid propellant industry to mold or form the solid propellant grain of rocket motors. The cured polyvinyl butyral layer provides improved mold release properties to the tooling.

Mold release technique for solid propellant casting tooling

A circular slit plate having slits therein that are symmetrically positioned and originate near the center of the plate and extend radially toward the outer diameter thereof is used to deaerate solid rocket motor propellant and to provide a uniform propellant flow distribution during rocket motor casting.

Method and apparatus for casting solid propellant rocket motors

Sodium chloride is added to water which is then passed through at least one electrolytic cell. There, electrolysis of the sodium chloride produces chlorine molecules and sodium hydroxide. The water is then flowed into the presence of metal-cyanide contaminants. The chlorine and caustic immediately react with the metal-cyanide compounds to produce metal hydroxide precipitates, while the cyanide is decomposed and liberated from the water in carbon dioxide and gaseous nitrogen. As part of this reaction, the sodium chloride is reformed, so that the same brine can be recycled and the process repeated without further additives. The optimum pH of between 7 and 8 may be maintained as needed by addition of small amounts of hydrochloric acid to the system.

Treatment of water containing cyanide

A method of making finely particulate ammonium perchlorate which comprises establishing a two-phase liquid system in which the upper phase is a concentrated solution of ammonium perchlorate and the lower phase is a liquid which is immiscible with the upper phase solvent and a non-solvent for ammonium perchlorate. Precipitation of ammonium perchlorate from the solution into the non-solvent is effected by either cooling the solution or evaporating the solvent thereof while subjecting the system to ultra-sonic vibrations. Fine ammonium perchlorate particles collect in the non-solvent phase and are recovered therefrom.

Growing community of inventors

Ogden, UT, United States of America

Larry W Poulter