Various examples are provided for hybrid tools including fixed-abrasive and loose-abrasive phases. In one example, a hybrid tool for finishing an internal surface of a workpiece includes a metallic rod and magnetic abrasive bonded to one or more defined portions of the metallic rod by an adhesive that dissolves when n contact with a lubricant used to finish the internal surface of the workpiece. In another example, a method for finishing an internal surface of a workpiece includes mounting the workpiece in a chuck of a lathe; positioning a hybrid tool inside an internal cavity of the workpiece using one or more pole-tips; providing an amount of the lubricant to the internal cavity; and rotating the workpiece with the lathe while controlling positioning of the hybrid tool inside the internal cavity using the one or more pole-types.

A hollow spring includes a steel tube in which the average of surface roughness is smaller than 10 m across the entire inner surface of the steel tube and/or compressive residual stress is given to the entire inner surface of the steel tube. The hollow spring may be manufactured by a step of polishing the inner surface of the steel tube by flowing a viscoelastic abrasive medium (200) within the tubular member (10), between a first opening (11) and a second opening (12) of the tubular member (10). The abrasive medium (200) may include a viscoelastic base material and a granular abrasive. The inner surface of the steel tube is polished evenly to reduce the surface roughness and/or is given compressive residual stress to increase the fatigue life of the hollow spring.

A method includes providing a metal ring and pastelessly slide-grinding at least one surface of the metal ring with grinding bodies, preferably until a predefined surface topography of the metal ring is achieved, which surface topography preferably has an Rsk value that is greater than or equal to 0.25 and/or an Rk value between 0.3 and 1.35 and/or Rpk value between 0.05 and 0.4 and/or an Rvk value between 0.2 and 1.2 and/or an Ra value between 0.1 and 0.4.

An impeller manufacturing method includes: integrally forming an impeller by an additive manufacturing method using a metal powder, the impeller including a disk which has a disk shape about an axis, a plurality of blades which are formed on a surface facing a first side in an axial direction of the disk with gaps therebetween in a circumferential direction about the axis, and a cover which covers the plurality of blades from the first side in the axial direction; processing the integrally formed impeller by a hot isostatic pressing; and causing a polishing fluid containing abrasive grains to flow through a flow path formed between the disk, the cover, and the blades in the impeller after the processing with the hot isostatic pressing and while pressurizing the polishing fluid to perform fluid polishing.

A method for abrasive flow machining includes moving an abrasive media through a high-aspect passage of a workpiece. Local pressure of the abrasive media is increased at target abrasion surfaces of the high-aspect passage using a passage geometry that is configured to direct flow of the abrasive media into the target abrasion surfaces such that the target abrasion surfaces are preferentially polished by the abrasive media over other, non-targeted surfaces of the high-aspect passage at which the flow of the abrasive media is not directed into.

A method for smoothing surface roughness within a passageway is disclosed. In various embodiments, the method comprises flowing an abrasive media through the passageway and positioning a mandrel within the passageway, the mandrel being sized to create a gap between an outer surface of the mandrel and an inner surface of the passageway, wherein the abrasive media is caused to flow through the gap, abrading the inner surface of the passageway.

An insert apparatus for protecting a curved inner surface within a passageway from abrasion during an abrasive machining operation is disclosed. In various embodiments, the insert apparatus includes a shield having a shell shaped to match a curved portion of the curved inner surface of the passageway and a shaft having a first end connected to the shell and a second end connected to a member configured to maintain the shaft within the passageway and the shell positioned against the curved inner surface during the abrasive machining operation.

A method for the surface finishing of workpieces moves the workpiece, including rotating about at least one axis, relative to a bed of a granular grinding and/or polishing material. The workpiece is accelerated to different speeds of rotation in relation to the bed of the granular grinding/polishing material. The workpiece or a container containing the bed of granular grinding/polishing material to be accelerated in periodic cycles of at most 5 sec between speeds of rotation and a second speed of rotation and/or to be rotated during continual acceleration at continually different speeds of rotation. A device for carrying out the method, such as a drag- or dip-finishing machine, includes a control device to impose speed of rotation profiles of the aforementioned type on a rotary drive workpiece holders, on which the workpieces can be clamped, or on a container containing the bed of granular material during the operation.

The present disclosure is directed to a system and method for in-situ (e.g. on-wing) cleaning of gas turbine engine components. The method includes injecting a dry cleaning medium into the gas turbine engine at one or more locations. The dry cleaning medium includes a plurality of abrasive microparticles. Thus, the method also includes circulating the dry cleaning medium through at least a portion of the gas turbine engine such that the abrasive microparticles abrade a surface of the one or more components so as to clean the surface.

A method for outer surface finishing of a workpiece may include coaxially placing the workpiece inside a vessel. The exemplary vessel may include at least one baffle that may radially extend from an inner wall of the vessel toward the outer surface of the workpiece. The exemplary method may further include pouring an abrasive medium inside the vessel, rotating the abrasive medium about the longitudinal axis in a first direction within the vessel relative to the outer surface of the workpiece by rotating the vessel about the longitudinal axis, and concurrently rotating the workpiece within the vessel about the longitudinal axis in a second direction, the second direction being opposite the first direction.