General Electric Company

Stephen Aleshin

Vanon D Pratt

Michael Jay Brunck

Christopher L English

Byron Andrew Pritchard, Jr

Paul J Monson

Eugene F Adiutori

Lorne A Weeter

A method for safeguarding regions of an airfoil adjacent to a work area from collateral damage as a result of laser operations. The method utilizes apparatus that includes a sensor assembly. The sensor assembly is fixedly attached to the laser nozzle assembly and moves with the laser nozzle assembly. The laser operations are controlled by a preprogrammed CNC controller. A fixture is used to position the workpiece in relationship to the nozzle on a laser table, the table movable in response to instructions from the controller. A beam stop material is placed over the regions of the airfoil adjacent to the work area to prevent back wall burn or to absorb reflected laser beam energy and to protect the region from other collateral damage such as stray material. The beam stop material is held in place on the workpiece and the workpiece is held in position on the fixture by elastomeric bands. On activation of the CNC program to perform the sequence of operations to accomplish preselected tasks, the laser nozzle performs as one of the operations in the sequence of operations an initial movement. The initial movement of the laser nozzle also causes movement of the sensor assembly. The sensor assembly detects the presence or absence of the elastomeric straps during the initial movement. If the elastomeric straps are detected, a signal is generated and sent to the controller, which then executes the remaining operations in the sequence of operations. If no signal is received by the controller, then the controller does not permit the sequence of operations to continue.

Laser beam stop sensor for automatically detecting the presence of laser beam stop material

Laser beam stop sensor and method for automatically detecting the presence of laser beam stop material using a laser beam stop sensor

Apparatus for performing laser weld repair of complex titanium-base material parts for gas turbine engines. The complex arts, typically compressor blisk airfoil assemblies are enclosed in a local dry box and purged in an inert gas atmosphere. Laser weld repairs are accomplished within this dry box by using a coaxial nozzle and a mixture of helium and argon. The welding is accomplished by maintaining a proper standoff between the weld nozzle and the weld. The welding is monitored and controlled from a remote location using in a video camera system. Copper shielding is provided within the dry box to protect areas adjacent to the weld area from overheating and weld spatter.

Apparatus for laser twist weld of compressor blisks airfoils

A method for repair welding a titanium compressor blisk using laser twist welding. A blisk assembly has damaged portions removed. The surface to be repaired is provided with a predetermined geometry. The portions to be repaired are surrounded by a fixture which contains a laser nozzle. The fixture can provide a protective atmosphere to the area under repair while also shielding adjacent areas from damage resulting form welding. The welding is accomplished using preprogrammed patterns. The welding within the fixture is monitored remotely and is adjusted when stand-off between the weld nozzle and the molten metal are not within a predetermined range.

Method for laser twist welding of compressor blisk airfoils

A coaxial single point powder feed nozzle includes an inner tube disposed coaxially within an outer tube. The inner tube has a powder inlet and powder outlet, and the outer tube has a gas inlet for receiving a shaping gas, and a single nozzle outlet. An intermediate portion of the outer tube is spaced radially outwardly from the inner tube to define an annular flow manifold therebetween which receives the shaping gas. The powder outlet is disposed coaxially with the nozzle outlet and is spaced therefrom to define an annular gas outlet for the manifold for channeling the shaping gas around the powder prior to discharge thereof from the nozzle outlet.

Coaxial single point powder feed nozzle

A device for observation and analysis of a cross-sectional portion of a stream of material, which may be either a particle or a fluid stream, includes a laser light source for generating a beam of light. A focusing lens is disposed in an optical path between the laser source and the stream and a plano-cylindrical lens of a selected focal length is disposed in the optical path between the focusing lens and the stream. The focusing lens and the plano-cylindrical lens convert the beam of light from the laser light source to a plane of light which may be projected through the stream to illuminate a selected cross-section of the stream for observation and analysis thereof.

Device and method for observing and analyzing a stream of material

An improved heat transfer assembly includes a textured impingement surface and means for impinging cooling air directly upon the textured surface. A component includes a surface textured to increase convective heat transfer with minimal increase in resistance to conductive heat transfer through the component. The textured surface can comprise an array of closely spaced hemispherically shaped protuberances. A method is disclosed for texturing a surface with discrete laser welds.

Enhanced impingement cooled components

A real time variable laser beam spinner, wherein a manual or programmable actuator angularly displaces a mirror or optical flat during rotation in order to follow the instantaneous spin diameter requirements associated with a workpiece, whereby a variable effective spin diameter of the beam results without interrupting the work process.

Real time variable laser beam spinner

An apparatus for welding together a plurality of portions of a workpiece with a complex geometric surface includes a laser source for generating a laser beam; the laser source is positioned at a predetermined distance from the workpiece portions to form a weld bead of a selected width. The apparatus also includes a powder feed mechanism with a nozzle for depositing a chosen volume of powder per unit of time onto the workpiece surface. The powder feed nozzle includes a structure for preventing a reflected laser beam from the workpiece surface and the weld bead from being incident upon an orifice of the nozzle and thereby preventing the powder from melting and clogging the nozzle orifice. Either the workpiece or the laser source in combination with the powder feed mechanism may be mounted on a manipulator arrangement for moving either the workpiece portions or the combination of the laser source and powder feed mechanism relative to one another to deposit the weld bead along a predetermined weld path.

Single point powder feed nozzle for use in laser welding

A method for depositing material on a tip of a gas turbine engine airfoil includes the steps of: selecting a linear principal weld path across the airfoil tip relative to an airfoil contour at the tip; selecting a weld bead stitch pattern to substantially completely cover the airfoil tip with the stitch pattern crisscrossing the linear principal weld path between opposite edges of the airfoil and advancing across the airfoil in the direction of the linear principal weld path; and depositing at least a first layer of tip material corresponding to the weld bead stitch pattern and the linear principal weld path by welding.

Growing community of inventors

Cincinnati, OH, United States of America

Stephen Aleshin