The disclosure relates to sintered ceramic grains comprising 3-55 wt. % alumina, 40-95 wt. % zirconia and 1-30 wt. % of one or more other inorganic components. The invention further relates to a method for preparing ceramic grains according to the invention, comprising: making a slurry comprising alumina, zirconia; making droplets of the slurry; introducing the droplets in a liquid gelling-reaction medium wherein the droplets are gellified; drying the gellified deformed droplets.

The present invention relates to a foam material comprising:—a structural matrix (1),—at least one guest phase (2), and—a fluid, the material being characterised in that the structural matrix (1) comprises a plurality of interconnected pores (3), the one or more guest phases (2) are accommodated inside at least one pore (3) of the structural matrix (1) and the fluid is accommodated inside the pores (3). The present invention further relates to the process for preparing the foam material according to the present invention and to the various uses of the foam material according to the present invention.

The present application discloses a ceramic preform, a method of making a ceramic preform and a metal matrix composite comprising a ceramic preform. In one exemplary embodiment, the ceramic preform comprises a ceramic compound compressed into the shape of a cylinder by rotational compression molding. The cylinder has an inner surface and an outer surface. A first liner may be attached to the inner surface of the cylinder and a second liner may attached to the outer surface of the cylinder. The metal matrix composite of the present application may be formed as a brake drum or a brake disc.

One aspect relates to a process for producing a sintered workpiece, which includes sintering of a ceramic material at a temperature of at least 1000° C. and in an atmosphere, in the case of which the partial pressure of atmospheric air is reduced to less than 10.sup.−6-times, based on the ambient air at the same temperature under equilibrium conditions.

One aspect relates to a process for producing a sintered workpiece, which includes sintering of a ceramic material at a temperature of at least 1000° C. and in an atmosphere, in the case of which the partial pressure of atmospheric air is reduced to less than 10.sup.−6-times, based on the ambient air at the same temperature under equilibrium conditions.

A composite member excellent in corrosion resistance of a substrate and excellent in heat radiation property is provided. A composite member includes a substrate composed of a composite material containing magnesium or a magnesium alloy and SiC and a coating layer provided on a surface of the substrate. The coating layer includes an outermost layer provided as an outermost surface and an intermediate layer provided directly under the outermost layer. The outermost layer contains nickel and phosphorus. The intermediate layer is mainly composed of copper. The intermediate layer has a thickness not smaller than 30 μm.

A refractory composition for forming a working lining in a metallurgical vessel contains a coarse-grain refractory particle fraction and a fine-grain refractory particle fraction, or at least 0.25% additive calcium oxide, or at least 0.25% titanium dioxide. The coarse-grain refractory particles can include alumina particles, magnesia particles, magnesium aluminate spinel particles, zirconia particles, or doloma particles, or a combination of any of these particles. The fine-grain refractory particles can be comprised of any low-magnesia refractory oxide. The refractory composition can be applied to a metallurgical vessel by spraying, gunning, shotcreting, vibrating, casting, troweling, or positioning preformed refractory shapes, or a combination of any of these techniques. When contacted by molten metal, the molten metal penetrates into the refractory material, wetting the coarse-grain refractory particles, and forming a refractory-metal composite barrier layer that decreases or blocks oxygen transport through the refractory lining.

A metal-silicon carbide-based composite material including: a composite part including a silicon carbide-based porous body constituted by a plurality of silicon carbide particles, and a metal that is infiltrated in the silicon carbide-based porous body; and first and second surface layers which contain a metal, and coat both main surfaces of the composite part. The metal contains at least one kind selected from the group consisting of aluminum and magnesium, and the amount of particles having a particle size of 300 μm or more in the plurality of silicon carbide particles is 5% by volume or less.

Ceramic-metallic composites are disclosed along with the equipment and processes for their manufacture. The present invention improves the densities of these composites by eliminating porosity through the use of a unique furnace system that applies vacuum and positive gas pressure during specific stages of processing. In the fabrication of Al.sub.2O.sub.3—Al composites, each process commences with a preform initially composed of at least 5% by weight silicon dioxide, and the finished product includes aluminum oxide and aluminum, and possibly other substances.

Provided are an aluminum-silicon-carbide composite having high thermal conductivity, low thermal expansion, and low specific gravity and a method for producing the composite. Provided is an aluminum-silicon-carbide composite formed by impregnating a porous silicon carbide molded body with an aluminum alloy. The ratio of silicon carbide in the composite is 60 vol % or more, and the composite contains 60-75 mass % of silicon carbide having a particle diameter of 80 m or more and 800 m or less, 20-30 mass % of silicon carbide having a particle diameter of 8 m or more and less than 80 m, and 5-10 mass % of silicon carbide having a particle diameter of less than 8 m.