Abstract:
La présente demande décrit un procédé d'assemblage d'au moins deux pièces (1, 2) en matériaux à base de carbure de silicium par brasage non-réactif, dans lequel on met en contact les pièces avec une composition de brasure (3) non-réactive, on chauffe l'ensemble formé par les pièces (1,2) et la composition de brasure (3) à une température de brasage suffisante pour faire fondre totalement ou au moins partiellement la composition de brasure (3), et on refroidit les pièces (1, 2) et la composition de brasure (3) afin de former après solidification de celle-ci un joint moyennement réfractaire; dans lequel la composition de brasure (3) non-réactive est un alliage binaire constitué, en pourcentages atomiques, de 60% à 66% de silicium et de 34 à 40% de nickel. Une composition de brasure (3) telle que définie ci-dessus, une pâte, suspension, de brasure comprenant une poudre de ladite composition de brasure et un liant organique sont également définies.
Abstract:
Une aube de turbomachine en matériau composite comprenant un renfort fibreux densifié par une matrice est fabriquée par un procédé comprenant : la réalisation par tissage tridimensionnel d'une ébauche fibreuse (100) en une seule pièce, la mise en forme de l'ébauche fibreuse pour obtenir une préforme fibreuse en une seule pièce ayant une première partie (102) formant préforme de pale et pied d'aube, au moins une deuxième partie (104) formant préforme de plateforme d'aube ou préforme de léchettes de talon d'aube, et au moins une troisième partie (106) formant préforme de renfort de plateforme d'aube ou préforme de becquets de recouvrement de talon d'aube, et la densification de la préforme fibreuse par une matrice pour obtenir une aube en matériau composite ayant un renfort fibreux constitué par la préforme et densifié par la matrice, et formant une seule pièce avec plateforme et/ou talon intégrés.
Abstract:
An embodiment of a PCD insert comprises an embodiment of a PCD element joined to a cemented carbide substrate at an interface. The PCD element has internal diamond surfaces defining interstices between them. The PCD element comprises a masked or passivated region and an unmasked or unpassivated region, the unmasked or unpassivated region defining a boundary with the substrate, the boundary being the interface. At least some of the internal diamond surfaces of the masked or passivated region contact a mask or passivation medium, and some or ail of the interstices of the masked or passivated region and of the unmasked or unpassivated region are at least partially filled with an infiltrant material.
Abstract:
An article of manufacture comprises a carbon-containing matrix. The carbon- containing matrix may comprise at least one type of carbon material selected from the group comprising graphite crystalline carbon materials, carbon powder, and artificial graphite powder. In addition, the carbon-containing matrix comprises a plurality of pores. The article of manufacture also comprises a metal component comprising Al, alloys of Al, or combinations thereof. The metal component is disposed in at least a portion of the plurality of pores. Further, the article of manufacture comprises an additive comprising at least Si. At least a portion of the additive is disposed in an interface between the metal component within the pores and the carbon-containing matrix. The additive enhances phonon coupling and propagation at the interface.
Abstract:
Densified composites of a metal such as copper or aluminum with a titanium- silicon-carbide or titanium-aluminum-carbide ceramic material are prepared by forming the ceramic material into a body, and infiltrating the body with the molten metal. The metal is able to rapidly penetrate into void spaces, between grain boundaries and even into the crystal structure of the ceramic grains to form a composite. The starting ceramic material may be previously densified, in which case various types of gradient structures can be produced easily. The process can be operated at low pressures, and so the hot pressing methods that normally must be used to densify these ceramic materials can be avoided.
Abstract:
The present invention relates to composite material comprising a layer of diamond material chemically bonded to a surface of a layer of silicon material, wherein the layer of diamond material comprises a mixture of diamond particles, silicon carbide and silicon and methods for producing the same.
Abstract:
A method and apparatus are disclosed for improving densification of porous substrate using a film boiling process. In particular, the disclosed method and apparatus permit more complete densification of a substrate (i.e., densification closer to the surface of the substrate) by providing a sort of barrier that reduces cooling of the surface of the substrate being densified caused by contact with the relatively cool boiling liquid precursor of the densifying material, such as carbon. In particular, contact between the substrate and the liquid precursor is reduced using one or both of physical barriers (such as a mesh material) or structures that promote the formation of an insulating gaseous layer between the substrate and the liquid precursor (such as a plate closely spaced apart from the surface of the porous substrate).
Abstract:
The invention provides a method for forming a carbon-containing material for a brake disc. The method comprises: (i) providing a porous body; (ii) introducing into the pores of the porous body a liquid suspension of particles comprising carbon; (iii) depositing the particles comprising carbon within the pores of the porous body; (iv) introducing into the pores of the porous body one or more precursor materials for forming or depositing a ceramic material, wherein the precursor material comprises a liquid suspension of ceramic particles and/or acid phosphate; (v) forming or depositing the ceramic material from the precursor material within the pores of the porous body.