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Turbine Components Corporation

Matthew Bernardo

Salvatore J Cretella

Ralph T DeMusis

Ralph T De Musis

A method of restoring the shroud of a turbine blade which has become worn, and particularly those edges of the shroud in the vicinity of what is commonly known as the Z-notch, which comprises the steps of grinding down the shroud in the vicinity of said notch to an accurately predetermined dimension with respect to the original geometry of the shroud, placing the blade in a fixture having a masking member with a slot in it, such that the Z-notch of the blade is disposed substantially in alignment with the slot, and depositing, by means of a plasma spray, a metal alloy onto those edges in an amount just sufficient to build up the same essentially to their original dimensions. Following the plasma spraying, the built-up edges are sintered at a temperature on the order of 1900.degree. F. or more, to more firmly bond the built-up layer to the base metal. The blade is then cooled. The resulting edges conform so closely to the original geometry of a new blade that no additional refinishing or grinding operations are normally required after the sintering.

Method of restoring the shrouds of turbine blades

A method of restoring the shroud of a turbine blade which has become worn, and particularly that edge of the shroud in the vicinity of what is commonly known as the Z-notch, which comprises the steps of grinding down the shroud in the vicinity of said notch to an accurately predetermined dimension with respect to the original geometry of the shroud, placing the blade in a fixture having a masking member with a slot in it, such that the Z-notch of the blade is disposed substantially in alignment with the slot, and depositing, by means of a plasma spray, a metal alloy onto the edge in an amount just sufficient to build up the same essentially to its original dimension. Following the plasma spraying, the built-up edge is sintered at a temperature on the order of 1900.degree. F. or more, to more firmly bond the built-up layer to the base metal. The blade is then cooled. The resulting edge conforms so closely to the original geometry of a new blade that no additional refinishing or grinding operations are normally required after the sintering.

A method of refurbishing vane or blade components. Used turbine vanes or blades are cleaned, annealed and in some cases slotted adjacent their ends, after which any cooling passages (in the case of vanes) are welded closed and all cracks welded over, on both leading and trailing edges. The trailing edge, for a vane or blade component having a short chord, is built up by welding along its full length with an alloy wire, after which any slots that were cut adjacent the ends are closed, also by welding. Then the worn surfaces of the vane or blade are built-up by a plasma spray process, using a metal powder with added silica, to a thickness which can be as great as 30 to 40 thousandths of an inch. The built-up vane or blade is then sintered and thereafter surface finished to conform to the original contour of the component when new. Any cooling holes are finally recut, and the vane or blade polished as required and inspected.

Method of refurbishing turbine vane or blade components

A refurbished turbine vane or blade. Used turbine vanes and blades are cleaned, annealed and in some cases slotted adjacent their ends, after which any cooling passages are welded closed and all cracks welded over, on both leading and trailing edges. The trailing edge, for a vane or blade having a short chord, is built up by welding along its full length with an alloy wire, after which any slots that were cut adjacent the ends are closed, also by welding. Then the worn surfaces of the vane or blade are built-up by a plasma spray process, using a metal powder with added silica, to a thickness as great as 30 to 40 thousandths of an inch. The built-up vane or blade is then sintered and thereafter surface finished to conform to the original contour of the component when new. Any cooling holes are finally recut, and the vane or blade polished as required and inspected.

Refurbished turbine components, such as vanes or blades

A machine for resurfacing the air-foil surfaces of turbine vanes and the like, comprising a base and a carriage movable over the base toward a work-performing station thereof. The base carries a power-driven abrasive belt which extends past the work-performing station, for engagement with the air-foil surface of the vane to be resurfaced. The latter is rotatably mounted on the carriage so as to be capable of turning during its engagement with the belt. The movement of the carriage over the base is governed by a cam and cam follower on the two parts, respectively, and a linkage is provided for effecting simultaneous synchronous turning of the cam and the vane. The arrangement is such that the position of the carriage with respect to the base is determined by the rotary position of the cam, and thus the contour of the latter affects the amount of resurfacing of the vane which occurs.

Turbine vane air-foil surface grinder

A method for repairing turbine vanes and the like which have become worn or cracked after extended periods of use. The method embraces the steps of applying molten metal containing a predetermined quantity of silicon to the cracks, and overall to the worn or eroded areas of the vane to build up the same beyond its original surface, sintering the vane in a furnace at a temperature of over 2,000.degree. F thereby burning off some of the silicon, allowing the vane to cool, and thereafter placing it in a high pressure furnace and subjecting it simultaneously to heating to a temperature in excess of 2,000.degree. F and a pressure in excess of 15,000 PSI to drive the build-up material into all of the cracks of the vane and simultaneously effect a densification of the material as well as improving the bond to the original eroded surfaces. Thereafter the vane is removed and allowed to cool, and the built-up surface of the vane is ground down so as to restore the dimensions of the piece substantially to those of a new part.

Method of refurbishing turbine vanes and the like

A refurbished turbine vane and method of producing the same. Used turbine vanes are cleaned, annealed and slotted adjacent their ends, after which the cooling passages are welded closed and all cracks welded over, on both leading and trailing edges. The trailing edge, for a vane having a short chord, is built up by welding along its full length with an alloy wire, after which the slots that were cut adjacent the ends are closed, also by welding. Then the worn surfaces of the vane are built-up by a plasma spray process, using a metal powder with added silica, to a thickness as great as 30 to 40 thousandths of an inch. The built-up vane is then sintered and thereafter surface finished to conform to the original contour of the blade when new. The cooling holes are finally recut, and the vane polished as required and inspected.

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West Haven, CT, United States of America

Matthew Bernardo