A sleeve may be configured to secure an airfoil cluster for polishing. The sleeve may include a mock airfoil and a bypass flow path between the mock airfoil and an end wall of the sleeve. The sleeve may be positioned in an annular ring of sleeves in a polishing apparatus. The polishing apparatus may comprise an annular flow path for an abrasive fluid. The abrasive fluid may be flowed through the annular ring of sleeves in order to polish the airfoil cluster.

A polishing method includes: a step of preparing a polishing device including a processing member and a suction mechanism configured to generate suction force; a step of setting a workpiece in the processing member; and a step of accelerating abrasive grains fed toward the workpiece to a predetermined speed with an air flow generated by operation of the suction mechanism, and polishing the workpiece by causing the abrasive grains to contact with or collide with the workpiece.

A polishing method includes: a step of preparing a polishing device including a processing member and a suction mechanism configured to generate suction force; a step of setting a workpiece in the processing member; and a step of accelerating abrasive grains fed toward the workpiece to a predetermined speed with an air flow generated by operation of the suction mechanism, and polishing the workpiece by causing the abrasive grains to contact with or collide with the workpiece.

An upper shield and a lower shield may be coupled to a rotor for polishing airfoils of the rotor in a vibratory bowl. The upper shield and the lower shield may include spars. The spars may correspond to leading edges and trailing edges of the airfoils. A media including abrasive particles may be flowed through the rotor in the vibratory bowl. The spars may protect the leading edges and trailing edges of the airfoils from excessive material removal by the abrasive particles.

A method for vibroblasting surfaces using a vibroblasting machine, said vibroblasting machine being equipped with at least one toroidal shaped process vat (50) which is set in a rotary motion and is suitable for containing workpieces whose surfaces are subjected to a vibroblasting processing, said method including a phase of inputting fine particles belonging to a sandblasting media into said process vat (50) to proceed with a sandblasting action of the surfaces of the workpieces being processed, and a phase of evacuation of said fine particles, characterized in that the phase of inputting fine particles belonging to the sandblasting media into said process vat (50) occurs from top to bottom or tangentially to the circumference of said process vat (50) and to the surface of the vibrating mass (75) of the workpieces and of the media.

An apparatus for cavitation peening is disclosed, including a fluid source, a conduit, and a portable nozzle assembly. The conduit includes a proximal end portion connected to the fluid source and a distal end portion connected to the portable nozzle assembly. The portable nozzle assembly includes an inner nozzle configured to channel a first stream of high-pressure fluid, and an outer nozzle configured to channel a second stream of low-pressure fluid concentrically around the first stream. The inner nozzle includes a cavitation insert having an inner passage with at least two reductions in cross-sectional area.

A reflector comprising a hollow body having an interior surface defining a passage through the hollow body, the interior surface having at least one optical surface part configured to reflect radiation and a supporter surface part, wherein the optical surface part has a predetermined optical power and the supporter surface part does not have the predetermined optical power. The reflector is made by providing an axially symmetric mandrel; shaping a part of the circumferential surface of the mandrel to form at least one inverse optical surface part that is not rotationally symmetric about the axis of the mandrel; forming a reflector body around the mandrel; and releasing the reflector body from the mandrel whereby the reflector body has an optical surface defined by the inverse optical surface part and a supporter surface part defined by the rest of the outer surface of the mandrel.

A reflector comprising a hollow body having an interior surface defining a passage through the hollow body, the interior surface having at least one optical surface part configured to reflect radiation and a supporter surface part, wherein the optical surface part has a predetermined optical power and the supporter surface part does not have the predetermined optical power. The reflector is made by providing an axially symmetric mandrel; shaping a part of the circumferential surface of the mandrel to form at least one inverse optical surface part that is not rotationally symmetric about the axis of the mandrel; forming a reflector body around the mandrel; and releasing the reflector body from the mandrel whereby the reflector body has an optical surface defined by the inverse optical surface part and a supporter surface part defined by the rest of the outer surface of the mandrel.

A method of smoothing an inner surface of a tubular wall of a workpiece is disclosed, including immersing the workpiece in a mixture of a liquid and an abrasive and inserting a cavitation peening nozzle into a cavity of the workpiece. The method further includes injecting a cavitating jet from the cavitation peening nozzle into the cavity.

Methods and devices for treatment of metal surfaces by means of electrically active solid particles that include a step of contact of the solid particles with the electrode of an electric source, a step of shooting the particles towards the metal surface to be treated and a step of transmission of electric charge of the particles on the metal surface to be treated. The transmission of the electricity between the electric source and the metal surface during the step of shooting preferably is by net charge of the particles or by electric conductivity by contact or by electric conductivity by means of voltaic arches. The current applied to the electrode is preferably a DC or a current that contains positive sections and negative sections.