A composite material having a grainy appearance, this composite material including a metal matrix which represents, in terms of volume fraction, between 50 and 95% of the grainy composite material, the ceramic particles having a diameter that lies in the range 0.1 to 2 mm and which represent, in terms of volume fraction, between 50 and 5% of the composite material are dispersed in the metal matrix and form the remainder of this grainy composite material. A method for manufacturing a grainy synthetic material.

A guide member for a fishing line including an alumina ceramic including Ti and Al, a content of Ti being not less than 0.5 mass % in terms of TiO.sub.2, a content of Al being not less than 92 mass % in terms of Al.sub.2O.sub.3, and a main phase of the alumina ceramic being alumina crystals, wherein a content ratio of aluminas crystal with an aspect ratio of not less than 2 within the alumina crystals is not less than 15%.

Refractory composite material based on Al.sub.2O.sub.3 in the form of corundum, SiO.sub.2 in the form of quartz and sodium aluminate having the formula NaAl.sub.11O.sub.17 or Na.sub.2O-11Al.sub.2O.sub.3, method for preparing the same, use thereof for preparing manufactured items, as well as manufactured items made thereby and use thereof.

In order to address the technical problem of allowing an unshaped refractory material using a spinel-containing alumina cement to provide further improved corrosion resistance and slag infiltration resistance while reducing the occurrence of crack/peeling, an unshaped refractory material is provided which comprises a refractory raw material mixture having a particle size of 8 mm or less, with the refractory raw material mixture having an alumina cement at least a part of which is a spinel-containing alumina cement, and, with respect to 100 mass % of the refractory raw material mixture, the alumina cement contains CaO in an amount of 0.5 to 2.5 mass %, and the spinel-containing alumina cement contains spinel in an amount of 3.5 to 10.5 mass %.

In a monolithic refractory, in terms of a proportion in 100 mass % of a refractory raw material having a grain size of 8 mm or smaller, an amount of Ca.sub.XSr.sup.1XAl.sub.2O.sub.4 (where, 0X0.5) is 0.5 mass % or more and 10 mass % or less, and a polyvalent metal salt of oxycarboxylic acid is 0.05 mass % or more and 1.0 mass % or less.

A refractory kiln car formed using a refractory composition has excellent resistance to high-temperature thermal shock and creep. The refractory composition is based primarily on chamotte having controlled particle sizes, and may also include mullite, fused silica, calcined alumina and microsilica, having controlled particle sizes. The refractory composition includes an aqueous colloidal silica binder that provides excellent castability and binding between the ingredients following drying.

The present invention relates to refractories with a composition gradient for lining the interior surface of combustion chambers. The invention envisages the use of refractories characterized by the presence of a number of layers with a different chemical composition to form a gradient along the cross section of the material. The presence of the composition gradient serves to combine the corrosion resistance of the surface layer, facing towards the inside of the combustion chamber, with the shock resistance of the bulk material.

The present invention relates to a porous aggregate, comprising Al.sub.2O.sub.3, SiO.sub.2 and optionally Fe.sub.2O.sub.3, having a d.sub.50 of equivalent pore diameter between 1 ?m or more and 50 ?m or below and a total porosity between 20% and 60%, for use in the formation of monolithic refractories. Also part of the invention is a method of formation for said aggregates, their use in the formation of monolithic refractories and monolithic refractories comprising such aggregates.

A refractory object can include at least approximately 10 wt % Al.sub.2O.sub.3 and at least approximately 1 wt % SiO.sub.2. In an embodiment, the refractory object can include an additive. In a particular embodiment, the additive can include TiO.sub.2, Y.sub.2O.sub.3, SrO, BaO, CaO, Ta.sub.2O.sub.5, Fe.sub.2O.sub.3, ZnO, or MgO. The refractory object can include at least approximately 3 wt % of the additive. In an additional embodiment, the refractory object can include no greater than approximately 8 wt % of the additive. In a further embodiment, the creep rate of the refractory object can be at least approximately 110.sup.6 h.sup.1. In another embodiment, the creep rate of the refractory object can be no greater than approximately 510.sup.5 h.sup.1. In an illustrative embodiment, the refractory object can include a glass overflow trough or a forming block.

Disclosed are ceramic bodies comprised of composite cordierite-mullite-aluminum magnesium titanate (CMAT) ceramic compositions having high cordierite-to-mullite ratio and methods for the manufacture of same.