Abstract:
Vessels selected from crucibles, pans, open cups and saggars essentially comprising of two components, from which (A) one component being a monolithic ceramic material, (B) the second component being a ceramic matrix composite, and wherein component (A) is the inner part, or inlay.
Abstract:
An apparatus can include a ceramic component, a metal component, and a glass sealing material that bonds the ceramic and metal components to each other. In an embodiment, the coefficients of thermal expansion of the components and glass sealing material can be within 4 ppm/°C of one another. The metal component may be relatively oxidation resistant. The glass sealing material may have a relatively low amount of an amorphous phase as compared to one or more crystalline phases within the glass sealing material. The apparatuses can exhibit good bond strength even after long term exposure to high temperature, thermal cycling to a high temperature, or both. In an embodiment, the metal component may allow another metal component of a different composition to be used without a significant impact on the integrity of the bonded apparatus.
Abstract:
A composite has a) a PMC layer, and b) a tile layer comprising a plurality of Ox/Ox CMC tiles each has: i) a central portion, ii) an outer portion disposed surrounding the central portion, the bottom surface of the outer portion is disposed flush with the bottom surface of the central portion, the tile layer forms a smooth continuous top surface and a smooth continuous bottom surface, and the tiles are disposed with respect to one another such that each tile is inverted with respect to an adjoining tile, and iii) one or more overlap joints formed by the overlapping of the outer portions of adjoining tiles, so that hot gases entering the smooth top surface of the tile layer between abutting outer and central periphery segments must travel laterally between the overlapping outer portions of adjoining tiles to reach the top surface of the PMC layer.
Abstract:
A method of forming one or more high temperature co-fired ceramic articles, comprising the steps of:- a) forming (34) a plurality of green compacts, by a process comprising dry pressing a powder comprising ceramic and organic binder to form a green compact; b) disposing (38) a conductor or conductor precursor to at least one surface of at least one of the plurality of green compacts to form at least one patterned green compact; c) assembling the at least one patterned green compact with one or more of the plurality of green compacts or patterned green compacts or both to form a laminated assembly; d) isostatically (40) pressing the laminated assembly to form a pressed laminated assembly; e) firing (42) the pressed laminated assembly at a temperature sufficient to sinter the ceramic layers together.
Abstract:
A manufacturing method for manufacturing a slice for making or repairing a heat protective coating of a hot gas path component of a gas turbine is provided. The manufacturing method includes debinding a prepreg made of at least two sheets containing powder bound by a binder and Spark Plasma Sintering the at least two debound sheets. Tape casting is used to make the tapes. The sheets can contain braze metal powder, ytterbium zirconate powder, yttria-stabilised zirconia powder or MCrAlY powder.
Abstract:
The invention relates to a method for the production of molded bodies from reaction-bonded, silicon-infiltrated silicon carbide and/or boron carbide, wherein a preform body is monolithically constructed in layers from an amorphous granulation using a physical or chemical curing or melting process, wherein the granulation comprises a proportion of at least 95 % of silicon carbide and/or boron carbide with an average grain size of 70 to 200 μm. The thus formed preform body is impregnated at least once with a soot suspension or carbon is introduced by gas phase deposition and, when brought into contact with liquid or gaseous silicon, it forms at a subsequent calcining secondary silicon carbide which solidifies a resulting infiltrated composite.
Abstract:
An improved method of sealing a ceramic part to a solid part made of ceramic, metal, cermet or a ceramic coated metal is provided. The improved method includes placing a bond agent comprising an Al 2 O 3 and SiO 2 based glass- ceramic material and organic binder material on adjoining surfaces of the ceramic part and the solid part. The assembly is heated to a first target temperature that removes or dissolves the organic binder material from the bond agent and the assembly is subjected to a second induction heating step at a temperature ramp rate of between about 100°C and 200°C per minute to temperatures where the glass- ceramic material flows and wets the interface between adjoining surfaces. The assembly is rapidly cooled at a cooling rate of about 140°C per minute or more to induce nucleation and re-crystallization of the glass-ceramic material to form a dense, durable and gas-tight seal.
Abstract:
Disclosed herein are methods for bonding refractory substrates, such as zircon substrates, without the use of a bonding agent. Exemplary methods include (a) providing a plurality of refractory components, each component having at least one surface to be bonded, (b) polishing each surface to be bonded to a surface roughness (R a ) of 200 nm or finer, (c) contacting the surfaces to be bonded to form an unbonded refractory substrate, (d) firing the unbonded refractory substrate, and (e) subjecting the surfaces to be bonded to a compressive force during firing. Methods for making refractory forming bodies are also disclosed herein.
Abstract:
Die Erfindung betrifft ein wärmedämmendes Isolationselement für Hochtemperaturanwendungen und ein Herstellungsverfahren dazu. Aufgabe der Erfindung ist es, Möglichkeiten für eine effektive Wärmedämmung und -Isolation anzugeben, die auch für Hochtemperaturanwendungen bei Temperaturen oberhalb 100 °C, bevorzugt oberhalb 500 °C eingesetzt werden können und dabei der erforderliche Raumbedarf sowie die Temperatur an der äußeren Oberfläche gegenüber herkömmlichen Lösungen reduziert ist. Ein erfindungsgemäßes wärmedämmendes Isolationselement für Hochtemperaturanwendungen weist eine äußere gasdichte Hülle auf. Im Inneren der Hülle ist ein Druck unterhalb des Atmosphärendrucks eingehalten und die Hülle ist aus einem keramischen Werkstoff gebildet. Außerdem ist die Hülle mittels eines temperaturstabilen Zusatzwerkstoffes in einem Fugenbereich oder an einer Öffnung stoffschlüssig gasdicht verschlossen. Allein oder zusätzlich kann aber auch ein Verschließen durch eine formschlüssige Verbindung erreicht werden. Dabei können für die Hülle verschiedene keramische Werkstoffe eingesetzt werden.