Mcdonnell Douglas Corporation

The Boeing Company

Mcdonnell Douglas Technologies Inc.

Henry W Babel

Steven A Daneman

Mark M Hasegawa

Douglas J Waldron

William F Bozich

Ronaldo Reyes De Jesus

Raymond H Anderson

Robert F Reizer

Krishnan K Sankaran

Huong Giang Le

Ronaldo R DeJesus

Colin D Chickles

Brian J Sova

Phillip L Fuson

Cherie A Jones

The present invention relates to methods of making large spin blanks out of pieces of aluminum sheet or plate joined by friction stir welding to provide plate blank sizes greater than 156 inch (396 cm) in diameter. Blank sizes greater than 209 inch diameter enable manufacturing possibilities for large one-piece spun parts instead of constructing large structures from pieces. This also applies to sheet, except that the maximum width obtainable is 139 inches (353 cm). The availability of large blank sizes, particularly for sheet, permits the use of traditional spinning where bending is the predominant method of metal movement rather than stretching and spinning. As the present invention is a very cost effective approach, it provides a method for producing significantly more economical spin blanks between 156 and 209 inches in diameter than are obtainable for a single piece blank.

Large diameter domes and methods of manufacturing same

A method to increase the toughness of the aluminum-lithium alloy C458 and similar alloys at cryogenic temperatures above their room temperature toughness is provided. Increasing the cryogenic toughness of the aluminum-lithium alloy C458 allows the use of alloy C458 for cryogenic tanks, for example for launch vehicles in the aerospace industry. A two-step aging treatment for alloy C458 is provided. A specific set of times and temperatures to age the aluminum-lithium alloy C458 to T8 temper is disclosed that results in a higher toughness at cryogenic temperatures compared to room temperature. The disclosed two-step aging treatment for alloy 458 can be easily practiced in the manufacturing process, does not involve impractical heating rates or durations, and does not degrade other material properties.

Method to increase the toughness of aluminum-lithium alloys at cryogenic temperatures

Large diameter dome tanks made of a plurality of plates friction stir welded together to form a blank and spun and/or stretched into form. The dome tanks may be for holding liquid rocket fuel. Methods of forming include friction stir welding two or more flat blanks together and spinning the combined workpiece into a hemisphere. The blanks may be sufficiently thick to enable stretching as well as spinning. Aluminum alloys may be used, and filler material may be included in thee friction stir welds to reduce grain growth and problems associated therewith in the spinning process.

Methods of manufacture of spin-forming blanks, particularly for fabrication of rocket domes

A metal substrate such as bare or anodized aluminum or an aluminum alloy having an inorganic white paint thermal control coating on the substrate, the coating having low solar absorptance and high infrared emittance, such as a potassium silicate binder having zinc oxide particles distributed therein, and a fluoropolymer topcoat such as polytetrafluoroethylene on the inorganic white coating, the topcoat having substantially no significant effect on the optical properties of the thermal control coating and having substantial adhesion to such coating and improved resistance to darkening under ultraviolet exposure in the outer space environment.

Durable protected optical coatings

An article is coated with a mixture of a high absorptance pigment, a low absorptance pigment, a low emittance material, and a high emittance binder. Each of the components of the coating are stable when exposed to a space environment. The amounts of the high absorptance pigment and the low absorptance pigment are selected to produce an absorptance of the coating of from about 0.20 to about 0.90, and the amount of the low emittance material is selected to produce an emittance of the coating of from about 0.25 to about 0.90. The low absorptance pigment is preferably a white pigment such as zinc oxide. The high absorptance pigment is preferably a black pigment such as cupric oxide, cobalt oxide, or manganese dioxide. The low emittance material is preferably a metal such as aluminum. The binder is preferably a ceramic such as potassium silicate.

Articles with stable coatings having tailorable optical properties

A metal substrate such as bare or anodized aluminum or an aluminum alloy having an inorganic white paint thermal control coating on the substrate, said coating having low solar absorptance and high infrared emittance, such as a potassium silicate binder having zinc oxide particles distributed therein, and a fluoropolymer topcoat such as polytetrafluoroethylene on the inorganic white coating, the topcoat having substantially no significant effect on the optical properties of the thermal control coating and having substantial adhesion to such coating and improved resistance to darkening under ultraviolet exposure in the outer space environment.

Process for protecting optical properties of a thermal control

A relatively impervious mechanical seal is formed between the outer surface of a tube and the inside surface of a mechanical fitting of a high pressure fluid or hydraulic system by applying a very thin soft metal layer onto the outer surface of the hard metal tube and/or inner surface of the hard metal fitting. The thickness of such thin metal layer is independent of the size of the tube and/or fittings. Many metals and alloys of those metals exhibit the requisite softness, including silver, gold, tin, platinum, indium, rhodium and cadmium. Suitably, the coating is about 0.0025 millimeters (0.10 mils) in thickness. After compression, the tube and fitting combination exhibits very low leak rates on the order or 10.sup.-8 cubic centimeters per second or less as measured using the Helium leak test.

High pressure mechanical seal

An elastomeric prepreg wherein a carrier, whether roving, yarn, broad goods or tape, is impregnated with an uncured elastomeric rubber system which may include the addition of modifiers to enhance the properties of the coating. The prepreg is capable of being spooled and de-spooled for subsequent filament winding or laid up into laminates. In either process no environmental control equipment is required as the volatiles have previously been removed, leaving the elastomer in the generally uncured state.

Elastomeric prepreg roving composite

A relatively impervious mechanical seal is formed between the outer surface of a tube and the inside surface of a mechanical fitting of a high pressure fluid or hydraulic system by applying a very thin soft metal layer onto the outer surface of the hard metal tube and/or inner surface of the hard metal fitting, prior to swaging the fitting onto the tube. The thickness of such thin metal layer is independent of the size of the tube and/or fittings. Many metals and alloys of those metals exhibit the requisite softness, including silver, gold, nickel, tin, platinum, indium, rhodium and cadmium. Suitably, the coating is about 0.0025 millimeters (0.10 mils) in thickness. After swaging, the tube and fitting combination exhibits very low leak rates on the order or 10.sup.-8 cubic centimeters per second or less as meaured using the Helium leak test.

A metal substrate such as aluminum or an alloy thereof having an ultraviolet sensitive thermal control coating on the substrate such as an anodic coating or a white thermal control paint coating, and an ultraviolet degradation protective coating on the thermal control coating. The ultraviolet degradation protective coating can be an ultraviolet absorber such as quartz or an ultraviolet reflector such as aluminum oxide.

Protection of thermal control coatings from ultraviolet radiation

An aluminum or aluminum alloy substrate having a low absorptance high emittance two-layer coating produced by first anodizing the substrate to form an anodic coating, followed by applying a topcoat of an inorganic white paint on the anodic coating, such dual layer coated substrate having spacecraft application, particularly for radiators.

Growing community of inventors

Huntington Beach, CA, United States of America

Henry W Babel