The invention relates to a method for producing a metal-ceramic substrate and to a furnace suitable for carrying out the method. With the method, a metal-ceramic substrate with increased thermal and current conductivity can be obtained. The method comprises the steps of providing a stack containing a ceramic body, a metal foil, and a solder material in contact with the ceramic body and the metal foil, the solder material comprising a metal having a melting point of at least 700° C., a metal having a melting point of less than 700° C., and an active metal, and heating the stack, the stack passing through a heating zone for heating.

The present invention relates to a method for producing a metal-ceramic substrate. The method has the following steps: providing a stack containing a ceramic body, a metal foil, and a solder material in contact with the ceramic body and the metal foil, wherein the solder material has: a metal having a melting point of at least 700° C., a metal having a melting point of less than 700° C., and an active metal; and heating the stack, wherein at least one of the following conditions is satisfied: the high temperature heating duration is no more than 60 min; the peak temperature heating duration is no more than 30 min; the heating duration is no more than 60 min.

A method for manufacturing a metal-ceramic substrate (1) includes providing a ceramic layer (10), a metal layer (20) and a solder layer (30) coating the ceramic layer (10) and/or the metal layer (20) and/or the solder layer (30) with an active metal layer (40), arranging the solder layer (30) between the ceramic layer (10) and the metal layer (20) along a stacking direction (S), forming a solder system (35) comprising the solder layer and the active metal layer (40), wherein a solder material of the solder layer (30) is free of a melting point lowering material and bonding the metal layer (20) to the ceramic layer (10) via the solder system (35) by means of an active solder process.

The invention relates to a process for producing a metal-ceramic substrate (1), comprising: providing a ceramic element (10) and a metal layer, providing a gas-tight container (25) that encloses the ceramic element (10), the container (25) preferably being formed from the metal layer or comprising the metal layer, forming the metal-ceramic substrate (1) by connecting the metal layer to the ceramic element (10) by means of hot isostatic pressing, wherein, for the purpose of forming the metal-ceramic substrate (1), an active metal layer (15) or a contact layer comprising an active metal is arranged at least in some sections between the metal layer and the ceramic element (10) for supporting the connection of the metal layer to the ceramic element (10).

In some examples, a method including forming a layer of a slurry composition between a first ceramic or CMC part and a second ceramic or CMC part. The slurry composition includes a carrier material; and a plurality of solid particles in the carrier material. The plurality of solid particles includes first silicon carbide (SiC) particles defining a first average particle size, second SiC particles defining a second average particles size that is less than the first average particles size, and reactive additive particles. The method includes heating the layer of slurry composition to react the plurality of reactive additive particles to fuse the plurality of first SiC particles and the plurality of second SiC particles together with the reactive additive particles, wherein the fused layer of the slurry composition forms a joint layer that joins the first ceramic or CMC part to the second ceramic or CMC part.

A method for manufacturing an optical element is a method for manufacturing an optical element in which laser light is transmitted, reciprocated, or reflected, and the method includes a first step of obtaining a bonded element formed by subjecting a first element part and a second element part, both being transparent to laser light, to surface activated bonding with a non-crystalline layer interposed therebetween; and after the first step, a second step of crystallizing at least a portion of the non-crystalline layer by raising the temperature of the bonded element. In the second step, the temperature of the bonded element is raised to a predetermined temperature that is lower than the melting points of the first element part and the second element part.

A method is described for assembling at least two parts made of silicon carbide based materials by non-reactive brazing in an oxidizing atmosphere, each of the parts comprising a surface to be assembled, wherein the parts are placed in contact with a non-reactive brazing composition, the assembly formed by the parts and the brazing composition is heated to a brazing temperature sufficient for completely or at least partially melting the brazing composition, or rendering the brazing composition viscous, and the parts and the brazing composition are cooled so as to form, after cooling the latter to ambient temperature, a moderately refractory joint. The non-reactive brazing composition is a composition A consisting of silica (SiO.sub.2), alumina (Al.sub.2O.sub.3), and calcium oxide (CaO), or a composition B consisting of alumina (Al.sub.2O.sub.3), calcium oxide (CaO), and magnesium oxide (MgO), and, before heating the assembly formed by the parts and the brazing composition to the brazing temperature, a supply of silicon in a non-oxidized form is carried out on the surfaces to be assembled of the parts to be assembled, and/or on the surface layers comprising the surfaces to be assembled of the parts to be assembled, and/or in the brazing composition.

A mullite sintered body according to the present invention has an impurity element content of 1% by mass or less and contains sintered mullite grains having an average grain size of 8 μm or less. When a surface of the mullite sintered body is finished by polishing, pores in the surface have an average largest pore length of 0.4 μm or less. The surface preferably has a center line average surface roughness (Ra) of 3 nm or less. The surface preferably has a maximum peak height (Rp) of 30 nm or less. The number of pores in the surface is preferably 10 or less per unit area of 4 μm×4 μm.

The object of the present invention is an integrally bonded composite component, a method for the production thereof, and the use thereof. The invention particularly relates to integrally bonded transparent ceramic composite components, to a method for the production of such ceramic composite components, and to the use thereof.

A method for manufacturing an optical element is a method for manufacturing an optical element in which laser light is transmitted, reciprocated, or reflected, and the method includes a first step of obtaining a bonded element formed by subjecting a first element part and a second element part, both being transparent to laser light, to surface activated bonding with a non-crystalline layer interposed therebetween; and after the first step, a second step of crystallizing at least a portion of the non-crystalline layer by raising the temperature of the bonded element. In the second step, the temperature of the bonded element is raised to a predetermined temperature that is lower than the melting points of the first element part and the second element part.