Abstract: The disclosure concerns an abrasive gas turbine blade tip cap preform for bonding to a blade tip to form an abrasive blade tip cap, the abrasive gas turbine blade tip cap preform being formed of a bonding layer and an abrasive layer, the bonding layer being a metallic layer comprising powder size particles of a nickel braze alloy and a nickel base superalloy, and the abrasive layer being a ceramic layer in a metal matrix comprising powder size particles of cubic boron nitride (cBN) and aluminum oxide (Al2O3) in a metal matrix of same composition of the bonding layer. The disclosure also concerns a method of manufacturing an abrasive gas turbine blade tip cap preform and a method of bonding the abrasive gas turbine blade tip cap preform to a blade tip to form an abrasive blade tip cap.

Abstract: A method for manufacturing a turbomachine component is disclosed, including the steps of producing, by additive manufacturing, a plurality of separate segments of the turbomachine component, having a skin surrounding an empty volume corresponding to a massive part of the turbomachine component; assembling the separate segments of the turbomachine component together forming a semi-finished component, with an empty cavity therein; filling cavity of the semi-finished component with a bulk flowable material; and densifying and solidifying the bulk flowable material in the cavity.

Abstract: In a hot isostatic pressing (HIP) method, the component to be treated, affected by imperfections, like porosity, cracks and cavities in its structure, is placed into a container together with non-metallic material in form of powder or grains having size greater than the porosity and the cracks and imperfections of the component. During the HIP process, the non-metallic material presses on the whole surface of the embedded component in order to generate a combination of temperature and forces capable to reduce defects, embedded and not embedded, in the component itself. The component is not contaminated during the process thus allowing easily removal of the non-metallic material by a simple operation of mechanical cleaning or chemical washing.

Abstract: A method for manufacturing impellers is described. The method provides for manufacturing a plurality of tubular components, each tubular component forming an inner passage, which is shaped as one of the flow passages of the final impeller. The tubular components are assembled together forming a semi-finished impeller. The semi-finished impeller is provided with annular cavities extending around the rotation axis of the impeller and gaps between adjacent tubular components. The gaps and cavities are filled with metal powder and the semi-finished impeller is subject to hot isostatic pressing, to densify the metal powder and form a monolithic final impeller.

Abstract: The method of protecting a component of a turbomachine from liquid droplets erosion provides covering at least one region of a component surface exposed to a flow of a fluid containing a liquid phase to be processed by the turbomachine with a protective layer. The protective layer consists of a plurality of adjacent sub-layers of different materials having high hardness in the range of 1000-3000 HV and low fracture toughness below 20 MPam1/2. The materials are typically nitrides or carbides of titanium or aluminum or chromium or tungsten. In an embodiment, the covering is carried out by a PVD technique, in particular by Cathodic Arc PVD, or a CVD technique. The method may be applied to any component of turbomachines, but it may be particularly beneficial for parts of centrifugal compressors.

Abstract: In a hot isostatic pressing (HIP) method, the component to be treated, affected by imperfections, like porosity, cracks and cavities in its structure, is placed into a container together with non-metallic material in form of powder or grains having size greater than the porosity and the cracks and imperfections of the component. During the HIP process, the non-metallic material presses on the whole surface of the embedded component in order to generate a combination of temperature and forces capable to reduce defects, embedded and not embedded, in the component itself. The component is not contaminated during the process thus allowing easily removal of the non-metallic material by a simple operation of mechanical cleaning or chemical washing.

Abstract: A method for manufacturing impellers is described. The method provides for manufacturing a plurality of tubular components, each tubular component forming an inner passage, which is shaped as one of the flow passages of the final impeller. The tubular components are assembled together forming a semi-finished impeller. The semi-finished impeller is provided with annular cavities extending around the rotation axis of the impeller and gaps between adjacent tubular components. The gaps and cavities are filled with metal powder and the semi-finished impeller is subject to hot isostatic pressing, to densify the metal powder and form a monolithic final impeller.

Abstract: A method of manufacturing a component of a turbomachine by powder metal hot isostatic pressing is disclosed, which uses a container defining outside surfaces of the component. A metal insert is located inside the container before filling the container with metal powder, and the insert is left in the component after the end of its manufacturing. In an embodiment, a metal core is located inside the container before filling the container with metal powder, and the core is removed from the component before the end of its manufacturing. In this way, net shape surfaces may be obtained without manufacturing trials.

Abstract: A method for manufacturing a turbomachine component is disclosed, including the steps of producing, by additive manufacturing, a plurality of separate segments of the turbomachine component, having a skin surrounding an empty volume corresponding to a massive part of the turbomachine component; assembling the separate segments of the turbomachine component together forming a semi-finished component, with an empty cavity therein; filling cavity of the semi-finished component with a bulk flowable material; and densifying and solidifying the bulk flowable material in the cavity.

Abstract: The method of protecting a component of a turbomachine from liquid droplets erosion provides covering at least one region of a component surface exposed to a flow of a fluid containing a liquid phase to be processed by the turbomachine with a protective layer. The protective layer consists of a plurality of adjacent sub-layers of different materials having high hardness in the range of 1000-3000 HV and low fracture toughness below 20 MPam1/2. The materials are typically nitrides or carbides of titanium or aluminum or chromium or tungsten. In an embodiment, the covering is carried out by a PVD technique, in particular by Cathodic Arc PVD, or a CVD technique. The method may be applied to any component of turbomachines, but it may be particularly beneficial for parts of centrifugal compressors.

Abstract: Devices and methods provide for an impeller for use in a compressor. A method for manufacturing the impeller includes: attaching an intermediate layer to a base metal by placing a first metal powder into a gap between a first insert and the base metal; processing with hot isostatic pressing the base metal, the first metal powder and the first insert such that the intermediate layer is bonded to the base metal; attaching an external layer to the intermediate layer by placing a second powder into a gap between a second insert and the intermediate layer; processing the base metal, the intermediate layer, the second metal powder and the second insert via hot isostatic pressing such that the external layer is bonded to the intermediate layer; and removing the second insert to form the impeller, wherein the external layer is corrosion resistant.

Abstract: Devices and methods provide for an impeller for use in a compressor. A method for manufacturing the impeller includes: attaching an intermediate layer to a base metal by placing a first metal powder into a gap between a first insert and the base metal; processing with hot isostatic pressing the base metal, the first metal powder and the first insert such that the intermediate layer is bonded to the base metal; attaching an external layer to the intermediate layer by placing a second powder into a gap between a second insert and the intermediate layer; processing the base metal, the intermediate layer, the second metal powder and the second insert via hot isostatic pressing such that the external layer is bonded to the intermediate layer; and removing the second insert to form the impeller, wherein the external layer is corrosion resistant.