Provided is a hearth roll for supporting and conveying a steel sheet in a continuous annealing furnace, wherein all of a shaft portion and a roil main body are made from one or more ceramic materials, preferably constituted with concentric ceramic layers of different ceramic materials centering on the rotation shaft of the roll. The hearth roll has not only an excellent pickup resistance but also a long roll life free from maintenance for long periods. Also provided is a continuous annealing facility using the hearth roll in at least one of a heating zone, a soaking zone and a cooling zone.

A cordierite-based sintered body according to the present invention contains cordierite as a main component and silicon nitride or silicon carbide. The cordierite-based sintered body preferably has a thermal expansion coefficient less than 2.4 ppm; ° C. at 40° C. to 400° C., an open porosity of 0.5% or less, and an average grain size of 1 μm or less.

A mullite-containing sintered body according to the present invention contains mullite and at least one selected from the group consisting of silicon nitride, silicon oxynitride, and sialon. It is preferable that the mullite-containing sintered body have a thermal expansion coefficient of less than 4.3 ppm/° C. at 40° C. to 400° C., an open porosity of 0.5% or less, and an average grain size of 1.5 μm or less.

A ceramic structure 10 includes a heater electrode 14 within a disk-shaped AlN ceramic substrate 12. The heater electrode 14 contains a metal filler in the main component WC. The metal filler (such as Ru or RuAl) has a lower resistivity and a higher thermal expansion coefficient than AlN. An absolute value of a difference |ΔCTE| between a thermal expansion coefficient of the AlN ceramic substrate 12 and a thermal expansion coefficient of the heater electrode 14 at a temperature in the range of 40° C. to 1000° C. is 0.35 ppm/° C. or less.

A composite production method includes impregnating a plate-shaped porous inorganic structure and a fibrous inorganic material with a metal while the fibrous inorganic material is arranged to be adjacent to the porous inorganic structure. In the composite structure, first and second phases are adjacent to each other by using a porous inorganic structure having a porous silicon carbide ceramic sintered body and the fibrous inorganic material, the first phase being a phase in which the porous silicon carbide ceramic sintered body is impregnated with the metal, the second phase being a phase in which the fibrous inorganic material is impregnated with the metal, a percentage of the porous silicon carbide ceramic sintered body in the first phase is 50 to 80 volume percent, and a percentage of the fibrous inorganic material in the second phase is 3 to 20 volume percent. A composite is produced by the method.

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 second mold is placed on a planar surface of a first mold to form a first mold cavity, which is filled with a first material slurry containing a first material powder and the molded slurry is caused to set, thereby forming a first molded part on the planar surface of the first mold. A third mold is placed on the planar surface of the first mold from which the second mold is removed and on which the first molded part is formed, thereby forming a second mold cavity. The second mold cavity is filled with a second material slurry which contains a second material powder different from the first material powder so as to mold the slurry in contact with the first molded part. The molded slurry is caused to set, thereby forming a second molded part on the planar surface of the first mold.

A ceramic substrate and a method for production thereof are provided, in which the ceramic substrate includes a composite of : a first ceramic layer including Sr anorthite and Al.sub.2O.sub.3 or an oxide dielectric with a dielectric constant higher than that of Al.sub.2O.sub.3; and a second ceramic layer including Sr anorthite and cordierite and having a dielectric constant lower than that of the first ceramic layer.

The invention relates to a method for producing a component from ceramic materials in which a plurality of layers are applied to a base body by means of screen printing or template printing, said layers being formed from a ceramic material, in each case in a defined geometry above one another in the form of a paste or suspension in which powdery ceramic material and at least one binder are included. At least one region is formed here within at least one layer having a defined thickness and geometry composed of a further material that can be removed in a thermal treatment and that is likewise applied in the form of a paste or suspension by means of screen printing or template printing. Electrically functional structures composed of an electrically conductive or semiconductive material are applied to and/or formed on and/or in at least of the ceramic layers prior to the application of a further ceramic layer. The layer structure is then sintered in a thermal heat treatment, with the further material being removed and at least one hollow space being formed with defined dimensions of width, length, and height.

Methods for forming ceramic matrix composite (CMC) components are provided. In one exemplary embodiment, a method comprises automatically laying up CMC plies. Laying up plies includes transferring a CMC ply to a layup tool; applying heat to the CMC ply; and stacking the CMC ply with at least one other CMC ply. In various embodiments, CMC plies may be laid up using an automated machine. In some embodiments, a CMC ply may be transferred to a layup tool using an automated machine and the CMC ply may be stacked with at least one other CMC ply using the automated machine.