United Technologies Corporation

Beth Kwiatkowski Abriles

Norman Pietruska

David A Rutz

David Norwood Potter

John H Hyde

Bryan W Manis

Walter E Olson

James J Moor

Edward R Szela

Timothy A Milleville

Murali N Madhava

John F Falkowski

A nickel base repair alloy comprises a blend of about 40 to 60 wt % of a first nickel based braze alloy containing boron, about 15 to 35 wt % of a first nickel based filler material, and the remainder consisting of a blend of a second nickel based filler material and a low melting eutectic braze nickel based alloy.

Nickel alloy for repairs

A process for repairing cracks in a workpiece, such as a turbine engine component, comprises the steps of: providing a workpiece having a crack to be repaired; applying a nickel or cobalt base alloy material to a root of the crack in an amount sufficient to fill a portion of the crack; subjecting the workpiece with the nickel or cobalt base alloy material to a first heat treatment at a temperature in the range of from about 1950 to 2300&#xb0; F. for a time period in the range of from about 5.0 to 30 minutes; applying a weld material to the crack; and subjecting the workpiece with the weld material to a second heat treatment.

Dual process nickel alloy crack repair

The present invention is directed to a process for repairing cracks in a turbine engine component. The process comprises the steps of providing a component, preferably formed from a single crystal nickel based material, with at least one crack, applying a repair alloy composition containing a single crystal nickel based alloy, a first nickel based braze alloy and a second nickel based braze alloy to the crack(s), and subjecting the component with the applied repair alloy composition to a thermal cycle to diffuse the repair alloy composition into the crack(s).

Low temperature diffusion braze repair of single crystal components

Methods for inspecting gas turbine component parts for possible distress after hydrogen fluoride cleaning are disclosed. The methods selectively remove a small amount of material for IGA inspection and restore the material using the same procedures as when the parts were manufactured.

Method for checking surface condition after cleaning

Novel materials and methods for repairing/reclassifying superalloy components are described herein. These materials are non-traditional blends of materials having a much higher base material content than traditional repair/reclassification materials. In embodiments used to repair/reclassify nickel-based components, these materials may comprise about 5-18.9 weight percent of a low melting point alloy and about 81.1-95 weight percent of a base material. In embodiments used to repair/reclassify cobalt-based components, these materials may comprise about 15-30 weight percent of a low melting point alloy and about 70-85 weight percent of a base material. These materials can be used to repair surface defects and/or build up worn or eroded areas of a component to meet precise dimensional and metallurgical requirements. These materials create robust repaired components having a dense, isothermally solidified structure having minimal borides and a high re-melt temperature.

Repair and reclassification of superalloy components

The present invention relates to a maskant system for use with a fluoride cleaning system. The maskant system comprises a parting compound applied to a surface which requires protection and a chromium rich maskant for substantially preventing intergranular attack and which reduces a depletion zone. The parting compound contains colloidal silica, de-ionized water, fused alumina grains, and alumina powder. The maskant is comprised of chromium powder mixed with a binder, a wetting agent, a thickening agent, and water. The maskant system may be used to clean components formed from nickel-based or cobalt-based alloys using a fluoride cleaning system and has particular utility when components formed from single crystal nickel based alloys are cleaned using a fluoride cleaning system.

Fluoride cleaning masking system

The present invention relates to a self cleaning braze paste which is used in the repair of gas turbine engines. The braze paste comprises lithium fluoride in an amount sufficient to act as a flux which allows the braze material to flow into a crack or void in a part to be repaired up to an amount where there is no residual lithium or fluoride in the crack or void, preferably up to about 20% by volume, a gel binder in an amount up to about 15% by volume, and the balance comprising at least one of a nickel braze alloy and a cobalt braze alloy. In a preferred embodiment, the lithium fluoride is present in an amount from about 10% to about 15% by volume. The braze material of the present invention may be applied in a paste form or, alternatively, in a paint or tape form. A method for cleaning and repairing a braze joint is also disclosed. The method broadly comprises the steps of forming a braze material containing lithium fluoride in the above mentioned range, a gel binder in an amount up to about 15% by volume, and the balance comprising at least one of a nickel braze alloy or a cobalt braze alloy, applying the braze material to the braze joint, and heating the braze material to a temperature in the range of from about a temperature sufficient to cause the lithium fluoride to volatize up to about 2300&deg; F. for a time period from about 1.0 minute to about 30.0 minutes.

Self cleaning braze material

A method and assembly useful in metal joining processes is disclosed which blocks the deposition of molten metal in openings. The method and assembly employs mica material with a binder to block the flow of molten metal. In one detailed embodiment, the mica material supports elements of the articles being brazed.

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Madison, CT, United States of America

Beth Kwiatkowski Abriles