Asea Aktiebolag

Allmanna Svenska Elektriska Aktiebolaget

Asea Ab

Sandvik Ab

Volvo Aero Corporation

Abb Cerama Ab

Asea

Asea Cerama Ab

Jan Nilsson

Hans Larker

Bertil Mattsson

Jan Adlerborn

Marianne Collin

Pertti Syvakari

Sven-Goran Gustafsson

Bertil Lundback

Hans Gunnar Larsson

Robert Lundberg

Lars Pejryd

Leif Hermansson

David Russberg

Erik Lundblad

Sten Johansson

Kjell Lilja

Eva Dahl

Martin Burstrom

Michael Goransson

Jan Svensson

A turbine including a rotor () that is driven by gas and that has a housing () enclosing the rotor. The turbine includes a component () suspended from the housing () that is arranged inside the housing () and at least partially beside the rotor () with respect to the direction () of the gas flow in order to impede any fragments which may come loose from the rotor from penetrating the housing in radial direction.

Turbine and a component

Method for manufacturing composites

According to the present invention there is provided a method of manufacturing a compound body having at least one, partly covering layer on a porous body, whose pore system is evacuate by means of a subpressure which is applied on the porous body by a suction cup or the like and the body is dipped in a slurry of powdery components of the layer. The compound body is densified by sintering or other heat treatment, e.g., post-HIP.

Method of manufacturing a compound body and the resulting body

Method for isostatic or pseudo-isostatic pressing employing a

An object is manufactured of a powdered material by isostatic pressing of a body (10), preformed from the powdered material, whereby the preformed body is surrounded by a casing (16) which at least for the main part is transferred to molten phase, before the isostatic pressing is carried out while sintering the powder. As material in the casing there is used glass or a material forming glass when being heated and containing 48-52 percent by weight B.sub.2 O.sub.3, 46-50 percent by weight SiO.sub.2 and 1.5-2.5 percent by weight Al.sub.2 O.sub.3. It can be removed from the finished object by water or water vapor and has a low coefficient of thermal expansion at temperatures below the melting temperature of the glass. To counteract the penetration of molten glass from the casing into the preformed body, a barrier layer (18) may be arranged on the preformed body inside the casing. (FIG. 3)

Method of manufacturing an object of a powdered material by isostatic

When manufacturing an object of powdered material by isostatic pressing of a body (10), preformed from the powdered material, with a gaseous pressure medium, the preformed body is provided with a casing (19) of glass which is made gas-impermeable by heating before carrying out the isostatic pressing. Inside the glass casing there is arranged on the preformed body a barrier layer (11) which counteracts the penetration of melted glass from the enclosure in the preformed body. The barrier layer is built up of at least two layers, of which one layer (12) at least substantially consists of powdered boron nitride and one layer (13) of a mixture of powdered boron nitride and a powdered material with the ability, upon contact with glass from the casing in melted form, to make a layer containing boron nitride tighter.

Method of manufacturing an object of powdered material by isostatic

A casting (e.g. of aluminum or aluminum alloy) is made at least approximately free from pores by being subjected, in heated state, to isostatic compression in a liquid pressure medium. A rapid pressing operation of under one minute can be achieved if the casting is placed in a container, the container and the casting are heated to the required compression temperature before they are thereafter placed in a press chamber of a fast-acting press. When liquid pressure medium is fed to the press chamber and the necessary pressure is applied thereto, the pressure medium flows into the interior of the container via a number of channels in its wall and is simultaneously heated to the necessary temperature, prior to its contacting the casting.

Method of reducing the pore density in a casting

In the manufacture of an article of ceramic material, for example a bladed turbine wheel of silicon nitride, there is first formed a plurality of article parts, at least one of which is a shaped powder body formed from powder of ceramic material mixed with a plasticizer, after which the plasticizer is driven off by a suitable heating operation. The article parts are then assembled together into a configuration conforming to that of the article to be manufactured, and the assembled article parts are surrounded with a gas-impermeable layer, for example a layer of glass. Finally, the assembled parts are isostatically pressed at elevated temperature to form the assembled article parts into a dense, homogeneous article.

Method of manufacturing articles of ceramic material

An object is manufactured from a powdered material by isostatic pressing of a body, preformed from the powdered material, with a pressure medium, whereby the preformed body, in which at least the surface layer consists of a ceramic material in the form of a nitride, is surrounded by a casing which is rendered impenetrable to the pressure medium, before the isostatic pressing is carried out and the powder sintered. As the material in the casing there is used boron oxide or a glass containing boron oxide or a material forming glass while being heated, in which the content of boron oxide is sufficiently high for the glass--or the glass formed during heating--to be removable by water. The preformed body surrounded by the casing is subjected to a heat treatment for the formation of boron nitride on the surface of the preformed body, before the isostatic pressing is carried out. The casing is removed from the finished product by means of water or water vapor.

Disclosed is a method for manufacturing an object of silicon nitride. In the method, a body preformed from silicon nitride is surrounded with a casing which is permeable to gas. Upon heating, the casing is transformed into a layer which is impermeable to a pressure medium which is used during isostatic pressing of the preformed body while a pressure outside the casing is maintained which is at least as high as the pressure of the gas which is present in the pores of the preformed product. After the casing has been made impermeable to the pressure medium and the preformed body has been enclosed therein, the isostatic pressing is carried out while the body is simultaneously sintered.

Method for manufacturing an object of silicon nitride

An object of ceramic or metallic material is manufactured by isostatic pressing of a body preformed from a powder of the metallic or ceramic material, the preformed body (10) then being embedded in glass, for example in a mass of glass particles (16) in a vessel (15) which is resistant to the temperature at which the sintering of the metallic or ceramic material is carried out, the material embedding the preformed body being transferred to a melt having a surface limited by the walls of the vessel, below which surface the preformed body is located, and a pressure necessary for the isostatic pressing of the preformed body then being applied on the melt by a gaseous pressure medium.

Method of manufacturing an object of metallic or ceramic material

Disclosed is an improved method for manufacturing an object of silicon nitride. In the method, a body preformed from silicon nitride powder and enclosed in a casing of glass is isostatically pressed with a gaseous pressure medium in a pressure vessel at a temperature required for sintering of silicon nitride. After pressing and sintering are completed, the pressure and the temperature in the pressure vessel are adjusted such that the temperature maintains the glass in a plastic state and the pressure in the pressure vessel is below the partial pressure of nitrogen gas for silicon nitride at that temperature so that the glass casing is blown up around the body and the body is freed from or can easily be freed from the glass casing.

Disclosed is a mandrel for a high pressure tube extrusion press. The mandrel comprises a tip member providing a tip adapted to be positioned in the die opening of the press to present an annular gap for tube extrusion, and a carrier for the tip member. The carrier has a threaded central tip member receiving bore for threadably receiving a threaded segment of the tip member therein. A divided ring shaped element is disposed between a flange on the tip member and the carrier in an annular space provided at the mouth of the bore to facilitate the assembly and disassembly of the mandrel and prevent inadvertent separation of the tip member from the carrier.

Mandrel for high pressure tube extrusion press

Method and apparatus for plastically de-forming material in a high pressure cylinder, the material being pre-formed into a mandrel billet with an attachment portion and a piston at respective opposite ends thereof and interconnected by an intermediate portion having a smaller cross section than the piston. Holder structure releasably mounted within the high pressure cylinder adjacent the pressure chamber retains the mandrel billet and includes securing means at one end for retaining the attachment portion and engagement means at the other end for slidably engaging the piston. Pressurization of the pressure chamber generates an increase in the pressure medium which acts on the transition surface between the intermediate portion and the piston to cause an elongation of the intermediate portion of the mandrel billet.

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Robertsfors, Sweden

Jan Nilsson