Abstract: When forming metallic components, in particular three-dimensionally curved blades, which constitute a single piece with the blading of turbomachine rotor wheels, the linear oscillation of the electrode acting as a tool is superimposed by a circular oscillation, enabling the electrode to turn into the workpiece conformally with its shape. Further forming is performed by circular oscillation with circular feed in the one and/or the other direction. An embodiment of the corresponding apparatus comprises an electrode holder (9) with linear feed (Zvor) and linear oscillation (Zosz) and a workpiece holder (5) with circular oscillation (Cosz) and circular feed (Cvor).

Abstract: When manufacturing slender metallic components (9) by cutting shaping from pre-manufactured forgings (1), the respective component (9) upon finish machining by cutting is dimensionally inspected to determine deformations (a) induced by manufacture, as compared to the nominal position, and on the basis of the measuring result the position of tensile stress areas (4) in rim layers of the component (9) is determined. For positionally balancing the component (9), the tensile stress areas (4) causing deformation of the component (9) are subjected to controlled shot peening at a specified intensity.

Abstract: A method for hard-material coating or heat treatment of the blade airfoils of blisks for gas turbines includes insulating portions of the blisk other than the blade airfoils against a furnace atmosphere; loading the blisk as a whole into a heat treatment furnace/coating cabinet at the required heat-treatment/coating temperature and partially cooling at least some of the insulated portions of the blisk with at least one of a solid and a liquid cooling medium while the blade airfoils are exposed to the temperature necessary for coating/heat treatment.

Abstract: Tip grinding of BLISK blades is performed in a static state of an incrementally rotatable BLISK, with a rotational axis (9) of a grinding wheel (4), which is traversable along an upper edge of the blade, being aligned diagonally to an orientation of the blade upper edge, and hence, in a direction of maximum resistance moment of the blades. The apparatus for the performance of the method features a locating device (7) for a BLISK which is incrementally rotatable by an auxiliary drive (8) as well as a high-speed shaft (3) driven by a main drive (2) for blade tip grinding of conventional rotor wheels fittable to the high-speed shaft (3). The grinding wheel (4) is traversable in Y-direction and rotatable about a center axis extending in X-direction, such that the blade tips in the static state can be ground in the direction of the maximum resistance moment of the blades.

Abstract: In the repair of a blisk or blisk drum, the damaged airfoils are completely cut off a low-stress nodal line of the respective blade, except for a blade stump (2), and are each replaced by a new blade repair element (3) of a same shape and size which is accurately clamped onto the blade root by a ledge (5) formed onto its mating end, with this ledge (5) also serving for fixation of the processing fixtures and stabilization of the thin airfoil, and is then welded to the blade root and subsequently subjected to a cutting or non-cutting operation for removal of the ledge (5). This highly efficient repair method can similarly also be applied to the new manufacture of blisks.

Abstract: A bore serration for locking externally serrated inserts (3) against rotation, with the external serration (4) comprising several teeth (5), and particularly for use with components made of hard, brittle materials, includes an arcuate serration (10) featuring arcuate recesses (7) produced by plunge or circumferential surface milling. Each of the recesses positively accommodates at least two teeth (5) of the outer serration (4) of the threaded insert (3). The arcuate serration can be produced with high dimensional accuracy without damaging the workpiece and with reduced wear of the tool, and ensures a long service-life of the threaded insert.

Abstract: A method for hard-material coating or heat treatment of the blade airfoils of blisks for gas turbines provides for partial heat-insulation and cooling of the other blisk parts during the respective process to prevent their properties from being changed by the high temperatures. The apparatus required for this method comprises two or more cooling plates (5 to 7) which are thermally insulated on their outer surfaces and include supporting flanges (20) which heat-conductively locate the blade platforms (3) of the blisks (1). Radially extending cooling medium channels (16) are provided in the cooling plates connected to a cooling medium source to continually apply cooling medium to the inner surfaces of the supporting flanges and the blade platforms.

Abstract: For the finish machining of turbine blades cast in titanium aluminide, the feeders (3) and runner portions (6) yielded by the casting process remain on the blade and serve as auxiliary clamping structure for clamping the blade to the workpiece carrier (15). In a position corresponding to the reference points for machining, clamping surfaces (12) with conical recesses (13), followed by threaded holes (14) are produced on the runners. For clamping the workpiece to a workpiece carrier (15), spring-loaded taper centering sleeves (18) arranged in the workpiece carrier or clamping bolts (21), respectively, engage the conical recesses and threaded holes, to enable the blade to be clamped and machined by way of the auxiliary clamping structure in the position corresponding to the reference points.

Abstract: When forming metallic components, in particular three-dimensionally curved blades, which constitute a single piece with the blading of turbomachine rotor wheels, the linear oscillation of the electrode acting as a tool is superimposed by a circular oscillation, enabling the electrode to turn into the workpiece conformally with its shape. Further forming is performed by circular oscillation with circular feed in the one and/or the other direction. An embodiment of the corresponding apparatus comprises an electrode holder (9) with linear feed (Zvor) and linear oscillation (Zosz) and a workpiece holder (5) with circular oscillation (Cosz) and circular feed (Cvor).

Abstract: When manufacturing slender metallic components (9) by cutting shaping from pre-manufactured forgings (1), the respective component (9) upon finish machining by cutting is dimensionally inspected to determine deformations (a) induced by manufacture, as compared to the nominal position, and on the basis of the measuring result the position of tensile stress areas (4) in rim layers of the component (9) is determined. For positionally balancing the component (9), the tensile stress areas (4) causing deformation of the component (9) are subjected to controlled shot peening at a specified intensity.

Abstract: When forming metallic components, in particular three-dimensionally curved blades, which constitute a single piece with the blading of turbomachine rotor wheels, the linear oscillation of the electrode acting as a tool is superimposed by a circular oscillation, enabling the electrode to turn into the workpiece conformally with its shape. Further forming is performed by circular oscillation with circular feed in the one and/or the other direction. An embodiment of the corresponding apparatus comprises an electrode holder (9) with linear feed (Zvor) and linear oscillation (Zosz) and a workpiece holder (5) with circular oscillation (Cosz) and circular feed (Cvor).

Abstract: A bore serration for locking externally serrated inserts (3) against rotation, with the external serration (4) comprising several teeth (5), and particularly for use with components made of hard, brittle materials, includes an arcuate serration (10) featuring arcuate recesses (7) produced by plunge or circumferential surface milling. Each of the recesses positively accommodates at least two teeth (5) of the outer serration (4) of the threaded insert (3). The arcuate serration can be produced with high dimensional accuracy without damaging the workpiece and with reduced wear of the tool, and ensures a long service-life of the threaded insert.

Abstract: Tip grinding of BLISK blades is performed in a static state of an incrementally rotatable BLISK, with a rotational axis (9) of a grinding wheel (4), which is traversable along an upper edge of the blade, being aligned diagonally to an orientation of the blade upper edge, and hence, in a direction of maximum resistance moment of the blades. The apparatus for the performance of the method features a locating device (7) for a BLISK which is incrementally rotatable by an auxiliary drive (8) as well as a high-speed shaft (3) driven by a main drive (2) for blade tip grinding of conventional rotor wheels fittable to the high-speed shaft (3). The grinding wheel (4) is traversable in Y-direction and rotatable about a center axis extending in X-direction, such that the blade tips in the static state can be ground in the direction of the maximum resistance moment of the blades.

Abstract: Repair of compressor blades (6) of aircraft engines is performed by build-up welding against an essentially horizontal backing (8) whose surface shape is the exact negative of the respective bottom side of the blade to be repaired. With low rework effort, the blades of blisks can, in the installed state, be repaired or fully restored at any point with high quality upon removal of the damaged portion.

Abstract: A method for hard-material coating or heat treatment of the blade airfoils of blisks for gas turbines provides for partial heat-insulation and cooling of the other blisk parts during the respective process to prevent their properties from being changed by the high temperatures. The apparatus required for this method comprises two or more cooling plates (5 to 7) which are thermally insulated on their outer surfaces and include supporting flanges (20) which heat-conductively locate the blade platforms (3) of the blisks (1). Radially extending cooling medium channels (16) are provided in the cooling plates connected to a cooling medium source to continually apply cooling medium to the inner surfaces of the supporting flanges and the blade platforms.

Abstract: On an apparatus for electrochemical precision machining, the tool holder (1) performing the oscillatory motion is supported by bearing bushes (25, 26) made of a swelling material within a casing (2) performing the feed motion. The swelling, cooling and lubricating liquid is supplied from liquid chambers (4, 5) provided in the casing. A further liquid chamber (6) prevents electrolyte from ingressing into the bearing bushes. The linear oscillatory motion of the tool holder is generated by a rocker (33) which is arranged vertically to the tool holder, extends through the casing and is driven by the eccentric (30) of a drive motor (29) with an associated frequency converter. A measuring device (42) and a fastener (43) enable the tool holder to be locked in a defined position, this permitting the apparatus to be operated with high accuracy also in the non-oscillating mode of the electrode.

Abstract: For the finish machining of turbine blades cast in titanium aluminide, the feeders (3) and runner portions (6) yielded by the casting process remain on the blade and serve as auxiliary clamping structure for clamping the blade to the workpiece carrier (15). In a position corresponding to the reference points for machining, clamping surfaces (12) with conical recesses (13), followed by threaded holes (14) are produced on the runners. For clamping the workpiece to a workpiece carrier (15), spring-loaded taper centering sleeves (18) arranged in the workpiece carrier or clamping bolts (21), respectively, engage the conical recesses and threaded holes, to enable the blade to be clamped and machined by way of the auxiliary clamping structure in the position corresponding to the reference points.

Abstract: In the repair of a blisk or blisk drum, the damaged airfoils are completely cut off at the same low-stress nodal line peculiar to the respective blade type, except for a blade stump (2), and are each replaced by a new blade repair element (3) of a same shape and size which is accurately clamped onto the blade root by a ledge (5) formed onto its mating end, with this ledge (5) also serving for fixation of the processing fixtures and stabilization of the thin airfoil, and is then welded to the blade root and subsequently subjected to a cutting or non-cutting operation for removal of the ledge (5). This highly efficient repair method can similarly also be applied to the new manufacture of blisks.

Abstract: When forming metallic components, in particular three-dimensionally curved blades, which constitute a single piece with the blading of turbomachine rotor wheels, the linear oscillation of the electrode acting as a tool is superimposed by a circular oscillation, enabling the electrode to turn into the workpiece conformally with its shape. Further forming is performed by circular oscillation with circular feed in the one and/or the other direction. An embodiment of the corresponding apparatus comprises an electrode holder (9) with linear feed (Zvor) and linear oscillation (Zosz) and a workpiece holder (5) with circular oscillation (Cosz) and circular feed (Cvor).

Abstract: A method for hard-material coating or heat treatment of the blade airfoils of blisks for gas turbines provides for partial heat-insulation and cooling of the other blisk parts during the respective process to prevent their properties from being changed by the high temperatures. The apparatus required for this method comprises two or more cooling plates (5 to 7) which are thermally insulated on their outer surfaces and include supporting flanges (20) which heat-conductively locate the blade platforms (3) of the blisks (1). Radially extending cooling medium channels (16) are provided in the cooling plates connected to a cooling medium source to continually apply cooling medium to the inner surfaces of the supporting flanges and the blade platforms.