A vacuum pump, vacuum pump set and method for evacuating a semiconductor processing chamber is disclosed. The vacuum pump is configured for mounting to a semiconductor processing chamber to evacuate the chamber to pressures between 1 mbar and 5×10.sup.−2 mbar. The vacuum pump comprises: a rotor rotatably mounted within a stator. The rotor comprises a plurality of angled blades arranged along a helical path from an inlet to an outlet. The stator comprises a plurality of perforated elements arranged to intersect the helical path, the perforations allowing gas molecules travelling along the helical path to pass through the perforated elements. The rotor mounted on a magnetically levitated bearing; and the perforated elements located towards an inlet of the vacuum pump comprise a transparency of more than 40% and the perforated elements located towards an outlet of the vacuum pump comprise a transparency of more than 30%.

The invention relates to an annular assembly for a dual-flow turbomachine having a longitudinal axis (A) and comprising a casing (12) with an annular shell (14), one face of which supports a piece of annular equipment, a plurality of means of attachment (18) for attaching the equipment to the annular shell (14) being distributed around the longitudinal axis (A) and allowing the equipment (16) a degree of freedom in the tangential direction relative to the annular shell (14), characterised in that each means of attachment (18) comprises a rail (20) integral with the annular equipment (16) and arranged radially between a first radially internal plate (22) and a second, radially external plate (24) and capable of sliding in the tangential direction between the first plate (22) and the second plate (24), and in that a removable support element (56) is securely connected to the annular shell and to the first plate (22) and second plate (24).

An impeller for a rotary machine includes: a base material of the impeller comprising Al or an Al alloy; a surface layer for the impeller formed by an electroless plating layer comprising a Ni—P based alloy; and an under layer disposed between the base material and the surface layer, the under layer having a smaller Vickers hardness than the surface layer.

An abradable powder composition is includes a metal component, a lubricant component, and a polymer component. A portion of the metal component is wrapped in the lubricant component to achieve high lubricity and abradability. The abradable powder composition can be used to form an abradable seal coating provided for use in a turbo machinery having a housing and a wheel having multiple blades. The housing houses the wheel which rotates therein. The seal coating is formed on the inner walls of housing adjacent where the wheel blades pass during their rotation. When the wheel is rotated such that, the blades contact the seal coating, it is abraded to form a close fit gap. The abradable seal coating preferably does not produce significant wear of the blade tips or transfer abradable material significantly to the blade tips upon being abraded.

A method for manufacturing an alveolar core structure includes at least one cell including a secondary duct having a first end defining a sound wave inlet, and an opposite second end, the secondary duct comprising a sound wave outlet. The method also includes a fastening step in which adhesive tapes transverse to the longitudinal direction of said first plate are applied on a first longitudinal plate. The secondary duct in the form of a flattened element is fastened, on the first plate, by gluing at its sound wave inlet. A second plate is applied. A step of deploying the first and second plates so as to form the peripheral wall of the cells and so that the flattened element is deployed.

A vacuum pump comprising: a rotor rotatably mounted within a stator; the rotor comprising a plurality of angled blades arranged along a helical path from an inlet to an outlet; the stator comprising a plurality of perforated elements forming a plurality of perforated discs arranged to intersect the helical path at different axial positions, the perforations allowing gas molecules travelling along the helical path to pass through the perforated elements. Each of the perforated discs comprises an outer curved wall forming an outer circumference of the disc and an inner curved wall forming a portion of an inner circumference of the disc, the inner circumference comprising at least one gap where there is no inner wall.

The present invention relates to a method for producing a multilayer film comprising aluminum, chromium, oxygen and nitrogen, in a vacuum coating chamber, the multilayer film comprising layers of type A and layers of type B deposited alternate one of each other, wherein during deposition of the multilayer film at least one target comprising aluminum and chromium is operated as cathode by means of a PVD technique and used in this manner as material source for supplying aluminum and chromium, and an oxygen gas flow and a nitrogen gas flow are introduced as reactive gases in the vacuum chamber for reacting with aluminum and chromium, thereby supplying oxygen and nitrogen for forming the multilayer film, characterized in that: —The A layers are deposited as oxynitride layers of Al—Cr—O—N by using nitrogen and oxygen as reactive gas at the same time, —The B layers are deposited as nitride layers of Al—Cr—N by reducing the oxygen gas flow and by increasing the nitrogen gas flow in order to use only nitrogen as reactive gas for the formation of the Al—Cr—N layer, and wherein the relation between oxygen content and nitrogen content in the multilayer film correspond to a ratio in atomic percentage having a value between and including 1.8 and 4.

A method includes applying a material coating on a surface of a machine component using a thermal spray, wherein the material coating is formed from a combination of a hardfacing material and aluminum-containing particles. The method also includes thermally treating the material coating to generate an oxide layer comprising aluminum from the aluminum-containing particles, wherein the oxide layer is configured to reduce oxidation of the hardfacing material.

A heat exchanger includes a plurality of fins arranged as a network and delimiting corridors, and an envelope having an internal wall and an external wall, the internal and external walls delimiting between them a channel for a flow of a first fluid in a main direction, the network of fins being arranged in the channel and connected to the internal and external walls, at least one passage for a flow of a second fluid being embedded in at least one of the internal and external walls, the channel being, in the main direction, divergent and then convergent.

Methods of protecting a metallic substrate from corrosion include introducing an aqueous or powder-form composition including at least one corrosion inhibitor into a crevice that traverses one or more layers covering the metallic substrate to deliver the composition via the crevice into contact with a surface of the metallic substrate. The corrosion inhibitors present in the composition bond to the surface of the metallic substrate, resulting in formation of a film on the surface of the metallic substrate. This film protects the surface of the metallic substrate against corrosion.