Rolls-royce Corporation

Gm Global Technolgoy Operations, Inc.

Allison Engine Company, Inc.

Rolls-royce North American Technologies Inc.

Stephen Norman Hammond

Lawrence E Brown

Udayan Trivedi

Thomas L Doubts

Douglas C Steckbauer

Raymond Ruiwen Xu

Peter W Heitman

Robert Anthony Ress, Jr

Randolph Clifford Helmink

Michael Cybulsky

Calvin W Emmerson

Richard Patrick Chesnes

Tetyana P Shmyreva

Sushil K Jain

Mark C Nordin

Elizabeth J Holmes

Robert A Testin

Jacque B Kennedy

In some examples, an article includes a substrate and a coating on the substrate. The coating includes a stabilized microstructure including Magn&#xe9;li oxide phase including an oxide of at least one of W, Mo, Nb, Ta, or Re. In some examples, a technique may include forming a coating including a refractory metal on a surface of a substrate. The technique also may include heat treating the coating at a temperature between about 500&#xb0; C. and about 700&#xb0; C. to form a coating including a stabilized microstructure including Magn&#xe9;li oxide phase. The stabilized microstructure including Magn&#xe9;li oxide phase may include an oxide of at least one of W, Mo, Nb, Ta, or Re. In some examples, the coating including the stabilized microstructure including Magn&#xe9;li oxide phase exhibits a coefficient of friction that is at least 25% less than the coefficient of friction exhibited by the as-deposited coating under similar conditions.

Thermally stable self-lubricating coatings

One embodiment of the present invention is a unique method for thermal mechanical processing of a martensitic stainless steel. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for thermal mechanical processing of a martensitic stainless steel and forged objects resulting therefrom. Further embodiments, forms, features, aspects, benefits, and advantages of the present application shall become apparent from the description and figures provided herewith.

Thermal mechanical processing of stainless steel

A carburizing process for increasing the hardness of a case region of a steel component. In one form the application includes plating the outer surface of a stainless steel component with nickel prior to carburizing. One component includes a stainless steel object having a hardened case substantially free of continuous phase grain boundary carbides.

Method for carburizing steel components

In one embodiment a centrifugal impeller has an axis of rotation, a plurality of blades, and a plurality of pitches defined between the blades. A cavity may be formed in a back side of the impeller, opposite with at least one of the plurality of pitches. In one form the cavity may not extend below a radius determined according to a stress criteria or stress limitation.

Gas turbine engine centrifugal impeller

The application contemplates a steel body having a hardened case portion and a core portion. The case portion has a hardness of at least Rc 50 and is substantially free of continuous phase grain boundary carbides. The steel body is formed of Pyrowear 675 which is a stainless steel material.

An electrospark alloying apparatus includes a main body member, a collet coupled to the main body member, and a heat sink adjacent the collet. The collet is adapted to receive and hold a consumable electrode. The apparatus can also include a drive for rotating the electrode. Further, the apparatus can include an inert gas supply and a discharge opening in the main body member for facilitating lamellar gas flow of insert gas from the inert gas supply around the electrode. A method of electrospark alloying includes electrospark alloying a workpiece with a consumable electrode and cooling the electrode during the electrospark welding.

Method and apparatus for electrospark alloying

The present invention generally relates to an external cylindrical or conic section shaped fixture which is tightly fit around the same shaped workpiece prior to expansion forming to a final dimension. During expansion forming, the external fixture is also deformed and is therefore designed for one-time use. The external cylindrical or conic section shaped fixture of the present invention is particularly useful for expansion forming of workpieces which contain brazed lap joints. The external fixture restrains, out-of-plane joint rotation and reduces the stress concentrations existing near the lap joints. Additionally, the external fixture provides additional load carrying capability to allow better load distribution during expansion forming. No change is required to the expansion forming machinery or the inner expander dies (jaws) with use of the present invention. Because the external fixture fits tightly over the workpiece, applying a compressive force when the inner expander jaws expand during the forming process, the bending moment on the brazed lap joints is significantly reduced.

Method and apparatus for expansion forming a workpiece using an external deformable supporting fixture

The present invention provides a brazing fixture and method of using the fixture which allows the brazing of a joint in an oxide-dispersion-strengthened (ODS) high temperature alloy workpiece where stresses in the workpiece operate to open the joint during the brazing process. The fixture is formed from the same ODS alloy as the workpiece, such that the fixture exhibits the same coefficient of thermal expansion as the workpiece. This allows maximization of surface area contact between the fixture and the workpiece during the brazing operation in order to force the workpiece to maintain its design dimensions and to prevent the joint from opening. The fixture includes a cavity preventing fixture/workpiece contact in the area of the braze to help control thermal lag in the area of the joint.

High temperature brazing fixture

Braze filler alloy is specifically applied and metallurgically bonded to a desired region of a nickel based superalloy workpiece using an electrospark deposition technique. The braze filler alloy is deposited onto, and concurrently metallurgically alloyed into, the desired region of the base metal by transfer of the material from the electrode using a short duration electrical impulse. The time and energy involved are small enough that total heat input to the base metal is minimal so that distortion and metallurgical structure changes of the base metal are negligible.

Method for depositing braze alloy to base metal surfaces using electric

Single crystal, nickel based superalloy turbine blades are formed by fusion welding together two matched blade halves. The matched blade halves are joined by an electrospark deposition process which deposits a weld filler metal along the matched faying surfaces. The deposited weld filler metal is preferably the same nickel based superalloy used to form the single crystal turbine blades. Total heat input to the base metal is minimal so that distortion and metallurgical structure changes of the base metal are virtually nonexistent.

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Brownsburg, IN, United States of America

Stephen Norman Hammond