United States of America As Represented by the Administrator of Nasa

Rtx Corporation

Frank L Palmieri

John W Connell

Christopher J Wohl, Jr

John W Hopkins

Tyler B Hudson

William T Yost

John D Riehl

Christopher J Hertel

Xiaomei Fang

Eric R Burke

Vincent B Cruz

Nancy M H Holloway

Fuh-Gwo Yuan

Rodolfo I Ledesma

Gary A Wainwright

Robert C Andrews

Jeffrey P Seebo

Martin Eckhard Zander

Nicolas Auwaijan

Wendell Keith Belvin

David W Sleight

Trenton B Abbott

Thomas J Burns

Methods and systems for the laser surface treatment on stainless steel alloys and nickel alloys may include a computer may be programmed to set a laser path corresponding to a predetermined geometric pattern. A laser may be coupled to the computer and apply a pulsed laser beam to a contact surface of the substrate along the predefined geometric pattern. The pulsed laser beam may have a laser power between 0.1 W and 100 W, single pulse fluence 1 mJ/mmand 1025 mJ/mmand a laser speed between 25.4 cm/s and 127 cm/s. The laser may generate an open pore oxide layer on the contact surface of the substrate with a thickness of 0.1-1 μm, an open pore distance of 0.05-1 μm. The open pore oxide layer may have a topography corresponding to the predefined geometric pattern. The topography may contain open pore structures and promote adhesive bond performance.

Laser surface treatment on stainless steel and nickel alloys for adhesive bonding

System and method for in-process cure monitoring of a material utilizes one or more sensors such as fiber Bragg gratings (FBGs) or phase-shifted FBGs (PS-FBGs) and at least one optical line fiber connected to the sensor(s). The sensor(s) and the optical line may be embedded in the material prior to curing the material may comprise a fiber reinforced polymer. Waves are excited into the material during curing thereof to form guided waves that propagate through the material. At least one wave metric of the guided waves is measured utilizing the sensor(s).

Guided wave-based system for cure monitoring of composites using piezoelectric discs and fiber Bragg gratings/phase-shifted Bragg gratings

Non-destructive evaluation (NDE) systems and methods are provided for monitoring objects being manufactured during a cure or consolidation process and for detecting defects that occur during the cure or consolidation process or to detect conditions of the process that can lead to the occurrence of defects. Information acquired by the NDE system during the cure or consolidation process can be used to adjust one or more parameters of the process in real-time to prevent defects from occurring or to reduce the number and/or severity of defects that occur during the cure or consolidation process.

Systems and methods for in-situ cure monitoring and defect detection

A soft lithography template or stamp is made by casting a polydimethysiloxane (PDMS) or other suitable elastomeric precursor onto a master pattern. The master pattern may be formed utilizing known micro-fabrication techniques. The PDMS template includes an inverse copy of the micro-structures on the master pattern, and can be placed into a mold used to prepare a carbon-fiber reinforced polymer composite part or other polymer molding systems where a matrix material passes through a fluid state during the cure process. The liquid resin material flows into the structures on the surface of the PDMS template and hardens during the curing cycle. After the part is released from the mold, the PDMS template can be peeled from the surface of the part to reveal the free standing micro structures which are a replica of the master pattern.

High pressure soft lithography for micro-topographical patterning of molded polymers and composites

Systems, methods, and devices of the various embodiments may enable simultaneous preparation of a substrate for adhesive bonding and detection of minute contaminants on the substrate. Various embodiments may enable detection of contaminants on a surface of a substrate while the surface of the substrate is being prepared for adhesive bonding by laser ablation. Various embodiments may provide an integrated laser treatment and measurement system.

Laser surface treatment and spectroscopic analysis system

A method for bonding composite substrates includes coupling a first co-cure prepreg layer having a first off-set amine to epoxide molar ratio onto a surface of a first composite substrate and coupling a second co-cure prepreg layer having a second off-set amine to epoxide molar ratio onto a surface of a second composite substrate. The first and second composite substrates are cured to the first and second co-cure prepreg layers, respectively, using a first cure cycle (including B-stage and cure temperatures) to form a first and a second co-cure prepreg layer portion. The method further includes coupling the first co-cure prepreg layer portion to the second co-cure prepreg layer portion and applying a second cure cycle to cure the first co-cure prepreg layer portion of the first composite substrate to the second co-cure prepreg layer portion of the second composite substrate to form a monolithic covalently bonded composite structure.

Off-set resin formulations and blocking/deblocking resin systems for use as a 'co-cure-ply' in the fabrication of large-scale composite structure

A method of forming a smooth aerodynamic surface that permits laminar flow of air over the smooth aerodynamic surface. Selected portions of a surface of a substrate material are ablated utilizing a laser to form a treated substrate surface having a predefined roughness. The treated substrate surface is coated to form a solid layer of material having a smooth aerodynamic surface that promotes laminar flow. The solid layer of material has a lower modulus of elasticity than the substrate material to provide durotaxis when an insect impacts the solid layer of epoxy material to thereby reduce adhesion of insect residue or other matter to the smooth aerodynamic surface.

Influence on surface interactions by substructure topography

A method for bonding composite structures which includes providing a first and second composite substrate and coupling a co-cure prepreg tape having chemically protected polymerizable functional groups onto a surface of both the first and second composite substrates. The first and second composite substrates are then cured to the co-cure prepreg tape at a first temperature to form a co-cure prepreg tape portion where the first and second composite substrates are fully cured and the co-cure prepreg tape is partially cured. The co-cure prepreg tape portion of the first composite substrate is then coupled to the co-cure prepreg tape portion of the second composite substrate and a deprotection initiator is applied to facilitate deprotection of the chemically protected polymerizable functional groups and cure the co-cure prepreg tape portion of the first and second composite substrates to form a single covalently bonded composite structure.

Blocking/deblocking resin systems for use as a 'co-cure-ply' in the fabrication of large-scale composite structure

A method for manufacturing a thin film structural system including a thin film structure includes depositing a reinforcing material in a liquid form in a predefined pattern on a thin film membrane, and transforming the reinforcing material in the predefined pattern to form a reinforcing element connected to the thin film membrane. The reinforcing material may be deposited in a melted form and solidified by cooling, may be transformed by a light or laser induced chemical reaction, or may be deposited and solidified such that the reinforcing element is at least partially embedded in the thin film membrane. The predefined pattern may redistribute loads around a damaged portion of the thin film structure, or define a hinge, a folding line, a stiffening feature. The reinforcing element may be electrically, optically or thermally conductive, to communicate with a device included in the system. The system may be a space structure.

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Hampton, VA, United States of America

Frank L Palmieri