Abstract: A composite and monolithic refractory structure, particularly adapted for making furnaces for glassmaking or the like, constituted by a block-shaped component made of electro-cast refractory material based on oxides of aluminum, zirconium, silicon, and the like, having shapes and dimensions that are adapted for its uses, inside which at least one protective element is monolithically inserted; the protective element is highly resistant to the attack of molten glass baths or the like and is chosen among metals, noble metals, refractory metals, refractory materials, conventional and non-conventional ceramic materials, such as carbides, nitrides, borides, and the like, or graphite-based materials, alloys and/or compounds and/or composites thereof; the element is provided substantially in the shape of a plate that is shaped and sized so as to have a profile that is similar to the peripheral profile of the refractory block and is arranged, inside the block, so that its surfaces are located at, and proximate to, the

Abstract: A ceramic body having a surface region containing tetragonal zirconia is sintered to at least 95% theoretical density at a temperature below about 1550 .degree. C. The surface region is then heat treated to reverse local stresses therein. Low temperature degradation in tetragonal zirconia, and materials containing tetragonal zirconia, is significantly inhibited. The heat treated ceramic is especially suited for use in structural components such as valves, engine housings, pistons (chambers) and the like which, during operation, are frequently exposed to temperatures ranging from room temperature to 500.degree. C. for prolonged periods of time.

Abstract: A sintered ceramic body which can be worked by electrical discharge machining, has high mechanical strength, and can be worked into sintered ceramic tools which have long life is disclosed. Further, sintered ceramic tools which have long life and scarcely cause flaws in work pieces are provided. The sintered ceramic body comprises ceramic particles having specific particle diameter and particle distribution.

Abstract: The present invention relates to a refractory binder that comprises a mixture of aqueous phosphate and silica sol. The silica sol has been found to gel and set in a surprisingly effective and useful way. Preferably, the refractory binder further incorporates a small amount of magnesia as an accelerator. The present invention also provides a method of binding a refractory material such, for example, as alumina, zirconia mullite or aluminium silicate by using a refractory binder according to the invention.

Abstract: An improved materials transporting element useful for transporting materials in sliding contact with a ware plate, for instance in materials feeder equipment, has a high precision, durable, wear and abrasion resistant sliding surface. The transporting element may have a tetragonal zirconia polycrystal ceramic sliding surface for reciprocal sliding contact with the ware plate having a zirconia-alumina sliding surface. Alternatively, the transporting element may have a zirconia-alumina ceramic composite sliding surface with the ware plate having a tetragonal zirconia polycrystal ceramic sliding surface.

Abstract: Thermally stable/highly reducible catalyst compositions, well suited for the catalytic conversion of exhaust gases emanating from internal combustion engines notably vehicular exhaust gases, comprise alumina, the oxides of cerium praseodymium and zirconium, and, optionally, at least one other oxide of bismuth, of a rare earth, or of an element of group VIII of the Periodic Table, and exhibit a stabilized hydrogen-absorption capacity up to a temperature of at least 1,000.degree. C.

Abstract: An alumina-zirconia sintered body comprising 92 to 35% by weight of aluminum oxide and 8 to 65% by weight of zirconium oxide having mainly tetragonal system, and 0.2 to 5 parts by weight of silicon oxide per 100 parts by weight of the total of aluminum oxide and zirconium oxide, and having a relative density of 95% or more, has improved wear resistance and suitable for use in an impact grinder.

Abstract: A zirconia based ceramic material having improved and well-balanced mechanical strength and toughness consists essentially of 0.5 to 50 vol % of Al.sub.2 O.sub.3 having an average grain size of 2 .mu.m or less and the balance of a partially stabilized zirconia having an average grain size of 5 .mu.m or less. The partially stabilized zirconia consists essentially of 8 to 12 mol % of CeO.sub.2, 0.05 to 4 mol % of TiO.sub.2 and the balance of ZrO.sub.2. Fine Al.sub.2 O.sub.3 grains having an average grain size of 1 .mu.m or less are dispersed within the grains of the partially stabilized zirconia at a dispersion ratio. The dispersion ratio is defined as a ratio of the number of Al.sub.2 O.sub.3 grains dispersed within the grains of the partially stabilized zirconia relative to the number of the entire Al.sub.2 O.sub.3 grains dispersed in the ceramic material, and at least 2% in the present invention. The ceramic material can be made by the following process.

Abstract: A thermal shock-resistant alumina-mullite composite material and a preparation method thereof which are capable of concurrently obtaining the compactness of the material and a mullite formation. The material is comprised of 4.about.30 weight % of one aluminum silicate selected from the group consisting of kaolinite, silimanite, and kyanite, 75.about.94 weight % of Al.sub.2 O.sub.3 based on the total amount of Al.sub.2 O.sub.3, and 0.5.about.6 weight % of an alkaline earth metal oxide, wherein the weight ratio of the alkaline earth metal oxide to SiO.sub.2 is 1:2.about.1:3. The composition is first sintered at a temperature of 1450.degree..about.1650.degree. C. for 1.about.5 hours, then cooled down to 1000.degree. C., and then crystallized at a temperature of 1200.degree..about.1500.degree. C. for 1.about.20 hours. This composition is usable to a maximum temperature 300.degree. C.

Abstract: Zirconium dioxide containing 2 to 40 vol. % of stabilizing oxides is embedded in the matrix material of a sintered molding consisting of an aluminum oxide/chromium oxide mixed crystal. The quantity of stabilizing oxides added is chosen so that the zirconium dioxide is predominantly tetragonal. The molar ratio of the zirconium dioxide containing the stabilizing oxides to the chromium oxide is between 1000:1 and 20:1 and the zirconium dioxide has a maximum particle size of 2 .mu.m.

Abstract: A zirconia material resistant to low temperature degradation and process for manufacturing thereof includes heat treating zirconia material or zirconia composite material at 1200.degree.-1700.degree. C. in the presence of nitrogen source.

Abstract: A refractory composition of a yttria-based, fused, solid solution of yttria, alumina, and zirconia. The composition provides advantages when used in a slurry for forming mold facecoats for investment casting molds.

Abstract: An alumina ceramic article and a method for preparing the article. The method comprises the steps of:(1) Compacting a mixture of a first concentration of particulate aluminum oxide sufficient to prevent retention of the zirconium oxide alloy particles in the surface in a predominantly tetragonal crystal structure and a second concentration of particulate zirconium oxide alloy. The zirconium oxide alloy is zirconium oxide and a secondary oxide selected from the group consisting of MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, CeO.sub.2, and rare earth oxides having a concentration of secondary oxide generally of about 0.5 to about 5 mole percent Y.sub.2 O.sub.3, from about 0.1 to about 1 mole percent MgO, from about 0.5 to about 15 mole percent CeO.sub.2, from about 0.5 to about 7.0 mole percent Sc.sub.2 O.sub.3, or from about 0.5 to about 5 mole percent CaO, relative to the total of the zirconium oxide alloy. The compacting results in the formation of a blank.

Abstract: A zirconia based ceramic material having improved and well-balanced mechanical strength and toughness consists essentially of 0.5 to 50 vol % of Al.sub.2 O.sub.3 having an average grain size of 2 .mu.m or less and the balance of a partially stabilized zirconia having an average grain size of 5 .mu.m or less. The partially stabilized zirconia consists essentially of 8 to 12 mol % of CeO.sub.2, 0.05 to 4 mol % of TiO.sub.2 and the balance of ZrO.sub.2. Fine Al.sub.2 O.sub.3 grains having an average grain size of 1 .mu.m or less are dispersed within the grains of the partially stabilized zirconia at a dispersion ratio. The dispersion ratio is defined as a ratio of the number of Al.sub.2 O.sub.3 grains dispersed within the grains of the partially stabilized zirconia relative to the number of the entire Al.sub.2 O.sub.3 grains dispersed in the ceramic material, and at least 2% in the present invention. The ceramic material can be made by the following process.

Abstract: The invention is directed to a non-vapor phase process for forming a metal/ceramic composite containing a relatively inert metal such as silver, copper, or nickel by the reaction of a reactive metal or metal alloy containing the inert metal, and a sacrificial ceramic preform. The resulting metal/ceramic composite is essentially the same shape and dimensions as the sacrificial ceramic preform, and exhibits improved physical and mechanical properties, including improved corrosion and wear resistance.

Abstract: The present invention is a ceramic article of magnesium-X silicate, wherein X represents lithium, sodium, potassium or other monovalent ion from about 0.1 to 2 weight percent, and yttria stabilized zirconia and alumina composite from about 99.9 to 98 weight percent wherein the yttria stabilized zirconia has a molar ratio of yttria to zirconia of from 0.5:99.5 to 5:95 and the alumina comprises from 0.1 to 50 percent of the yttria stabilized zirconia and alumina composite.

Abstract: A method for preparing a ceramic composite having a core/bulk of tetragonal zirconia alloy and a shell/surface comprising zirconium boride by sintering a zirconia or zirconia and alumina composite article in an argon atmosphere while in contact with boron carbide.

Abstract: A ceramic article containing a core/bulk comprising tetragonal zirconia or tetragonal zirconia and alumina composite wherein zirconia is preferably doped with yttria, and a shell/surface comprising zirconium boride.

Abstract: Electrically conductive ceramic composite articles comprising tetragonal zirconia or a composite of zirconia-alumina and zirconium diboride.

Abstract: A porous ceramic material for a slidable member on unit such as a valve unit of a combination faucet. The porous ceramic material comprises a ceramic sintered body which is formed with pores dispersedly located therein. The pores are defined respectively by surface layers forming part of the ceramic sintered body. Each surface layer contains silicon in a content higher than that in other part of the ceramic sintered body. The porous ceramic material is prepared, for example, first by mixing ceramic powder and hollow particles each of which contains silicon so as to obtain a mixture; then by forming the mixture into a predetermined shape to obtain a formed body; and finally by sintering the formed body at a temperature higher than a melting point of each hollow particle to thus obtain the sintered body formed with pores and containing silicon.

Abstract: A platelet .alpha.-Al.sub.2 O.sub.3 based ceramic composite consists of Al.sub.2 O.sub.3 powder, promoters and controllers. The composite is prepared by mixing aluminum oxide powder with promoters and controllers. The mixture is shaped and sintered to form an object. In one embodiment of the invention, the promoters are either salts or oxides of alkaline metals and alkaline earth metals. The salts are oxidized during sintering.

Abstract: Provided is a refractory for casting which contains clinker having a mineral crystal phase consisting essentially of mullite and baddeleyite. The refractory for casting has excellent in a thermal-shock resistance, corrosion resistance and strength. The refractory for casting is manufactured from a raw material containing a refractory composition and an organic binder, wherein the refractory composition comprises(a) 3 to 60 wt % of clinker having a mineral crystal phase consisting essentially of mullite and baddeleyite, and containing 5 to 22 wt % of alumina (Al.sub.2 O.sub.3), 38 to 68 wt % of zirconia (ZrO.sub.2) and 27 to 40 wt % of silica;(b) 5 to 40 wt % of at least one carbon-based material selected from the group consisting of graphite and carbon; and(c) at least one refractory element as a balance, selected from the group consisting of alumina, fused silica, zirconia, silicon carbide, mullite and a metal silicon.

Abstract: An alumina ceramic article and a method for preparing the article. The method comprises the steps of:(1) Compacting a mixture of a first concentration of particulate aluminum oxide sufficient to prevent retention of the zirconium oxide alloy particles in the shell in a predominantly tetragonal crystal structure and a second concentration of particulate zirconium oxide alloy. The zirconium oxide alloy is zirconium oxide and a secondary oxide selected from the group consisting of MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, CeO.sub.2, and rare earth oxides having a concentration of secondary oxide generally of about 0.5 to about 5 mole percent Y.sub.2 O.sub.3, from about 0.1 to about 1 mole percent MgO, from about 0.5 to about 15 mole percent CeO.sub.2, from about 0.5 to about 7.0 mole percent Sc.sub.2 O.sub.3, or from about 0.5 to about 5 mole percent CaO, relative to the total of the zirconium oxide alloy. The compacting results in the formation of a blank.

Abstract: A ceramic which is thermal shock resistant and which is a sintered, homogeneous mixture of first and second ceramic powders, including a first ceramic powder which is based on at least one tetravalent oxide selected from the group including zirconium dioxide, hafnium dioxide, and thorium dioxide, and which is further composed of at least one stabilizer oxide selected from the group including oxides effective to stabilize the at least one tetravalent oxide; and a second ceramic powder which is based on at least one tetravalent oxide selected from the group including zirconium dioxide, hafnium dioxide, and thorium dioxide, which contains from 0 to 2.5 mole % of at least one stabilizer oxide based on that molar amount of Y.sub.2 O.sub.

Abstract: High-zirconia fused refractories consist essentially of 85-96 wt % of ZrO.sub.2, 3-8 wt % of SiO.sub.2, 0.1-2 wt % of Al.sub.2 O.sub.3, 0.05-3 wt % of B.sub.2 O.sub.3, 0.05-3 wt % of BaO, SrO and MgO in total, 0.05 wt % or more of Na.sub.2 O, 0.05-0.6 wt % of Na.sub.2 O and K.sub.2 O in total, and 0.3 wt % or less of Fe.sub.2 O.sub.3 and TiO.sub.2 in total, and does not substantially contain P.sub.2 O.sub.5 and/or CuO.

Abstract: A ceramic article containing a core comprising zirconia and ZrB.sub.2 composite wherein zirconia is preferably doped with yttria, and a shell comprising zirconium nitride.

Abstract: There is now provided a ceramic material comprising of alumina, 10-50% by volume, preferably 20-35% by volume, silicon carbide whiskers, 1-25% by volume, preferably 5-20% by volume, most preferably 7-15% by volume, zirconia and 1-20% by volume, preferably 3-15% by volume, titanium compound-containing cubic phase. If this cubic phase has a lattice spacing of 4.29 to 4.40 .ANG. and a zirconium content of 3-65 weight %, a material with improved performance when turning heat resistant material such as aged Iconel 718, is obtained.

Abstract: The present invention provides a method for preparing a ceramic mixed-oxide of at least two metals including mixing an alloy with a ceramic oxide. The alloy including a metal selected from the group consisting of aluminum, calcium, lithium, magnesium, silicon, titanium, yttrium, and zirconium. The alloy also includes an element that is to be present in the ceramic mixed-oxide. The element is different from the metal and is selected from the group consisting of aluminum, calcium, lithium, magnesium, a combination of magnesium and silicon, silicon, titanium, yttrium, and zirconium. The ceramic oxide includes a metal that is to be present in the ceramic mixed oxide. The alloy and ceramic oxide are co-milled. The mixed and co-milled alloy and ceramic oxide are reaction-sintered, thereby oxidizing the metal and element of the alloy to produce the ceramic mixed-oxide.

Abstract: A ceramic electromagnetic window made of Si.sub.3 N.sub.4 particles which are bonded together by a metal phosphate binder that is an AlPO.sub.4 binder, a ZrP.sub.2 O.sub.7 binder, or mixtures thereof, wherein the Si.sub.3 N.sub.4 particles comprise from 55 to 85 volume percent of the ceramic material of the electromagnetic window with the metal phosphate binder comprising the remainder. By substituting Si.sub.3 N.sub.4 whiskers for some of the Si.sub.3 N.sub.4 particles a discontinuous fiber composite ceramic electromagnetic window is produced. The electromagnetic window may be a simple shape such as a flat or slightly curved sheet or a more complex shape such as a conical or spherical radome.

Abstract: A process is described for the production of alumina/zirconia materials which uses cheap scrap alumina/zirconia/silica material as feedstock along with a reducing agent to lower the final silica content to an acceptable level.

Abstract: A blade for the use of a rotary compressor includes a sintered body composed of 50 to 98.5 wt. % of zirconia, 1 to 49.5 wt. % of alumina and the reminder including 0.5 to 10 wt. % of a stabilizing material. The stabilizing material is comprised of at least one selected from magnesia, calcia, ceria and an oxide of an rare-earth metal and the grain size of the sintered body is less than 3 .mu.m. The zirconia in the sintered body is substantially formed with a tetragonal structure or a mixture of tetragonal and cubic structures.

Abstract: A method of preparing a mixture of zirconia and a stabilising agent for the zirconia comprises milling an aqueous suspension of particulate zirconia and particulate stabilising agent in a bead mill for at least 2 minutes in the presence of a particulate mixing medium having an average particle size from 0.2 mm to 3 mm. Preferred stabilising agents are oxides of yttrium, cerium, calcium or magnesium. Surprisingly, ceramics prepared from the product mixture are more resistant to degradation by attack from water above 100.degree. C. than are ceramics prepared from coprecipitated powders.

Abstract: The invention relates to an abrasive material based on .alpha.-Al.sub.2 O.sub.3 and ZrO.sub.2 with a content of titanium compounds in the form of suboxides, carbides and/or oxycarbides, to a process for its production and to its use.

Abstract: A zirconia based composite material with improved strength and toughness includes a partially stabilized zirconia including 1.5 to 4.5 mol % of yttrium oxide as a matrix thereof and a metal phase of at least one metal selected from the group consisting of titanium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten as metal grains dispersed in the matrix. The metal phase has a melting point higher than a sintering temperature of the partially stabilized zirconia. In addition, it is preferred that the composite material further contains a ceramic phase of at least one ceramic selected from the group consisting of Al.sub.2 O.sub.3, SiC, Si.sub.3 N.sub.4, B.sub.4 C, carbides, nitrides and borides of titanium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten as ceramic grains dispersed in the matrix. The composite material of the present invention is manufactured by the following steps.

Abstract: The invention relates to fused ceramic beads, which have the following chemical composition in % by weight on the basis of the oxides:40 to 95% of ZrO.sub.2 and HfO.sub.2 ;at least one of Y.sub.2 O.sub.3 and CeO.sub.2, with the provisos that Y.sub.2 O.sub.3, when present, represents 0.1 to 10% and CeO.sub.2, when present, represents 1 to 25%, the total of Y.sub.2 O.sub.3 and CeO.sub.2 representing 0.1 to 25%;a quantity of SiO.sub.2 representing 10 to 45% of the composition when CeO.sub.2 is absent from the composition and 0.5 to 45% when CeO.sub.2 is present in the composition. Application to grinding and to dispersion in wet medium is provided.

Abstract: The present invention relates to non-magnetic ceramic substrate material for magnetic head having similar thermal expansivity to the metal magnetic thin film, abrasion resistance during contact traveling of the magnetic tape and good processability and thus increasing lifetime by preventing exfoliation and crack of the magnetic thin film. The material comprises 10-35 mol % of CaO, 10-40 mol % of TiO.sub.2, 10-60 mol % of NiO and 10-50 mol % of CoO.

Abstract: The invention relates to the thermal barriers, to a process and material for their production, and to their application. Thermal barriers consist of a material comprising at least one refractory oxide with low thermal diffusivity and at least one quasicrystalline aluminum alloy, the proportion of which represents from 2-30% by volume. They can be produced by deposition of a mixture of refractory oxide and of quasicrystalline alloy in vapor phase, or from a mixture of refractory oxide and quasicrystalline aluminum alloy in the molten state, or else by deposition onto the support to be protected with the aid of an oxygen-gas torch fed with material using a flexible cord which contains the refractory oxide and the quasicrystalline alloy. The applications include the protection of components of aircraft or motor vehicle engines, of aeronautical or aerospace components, of chemical reactors or of electrical households appliances.

Abstract: High zirconia fused cast refractories which include as chemical components of refractories in weight %, 85 through 91% of ZrO.sub.2, 7.0 through 11.2% of SiO.sub.2, 0.85 through 3.0% of Al.sub.2 O.sub.3, 0.05 through 1.0% of P.sub.2 O.sub.5, 0.05 through 1.0% of B.sub.2 O.sub.3 and 0.01 through 0.12% of a summed amount of K.sub.2 O and Na.sub.2 O, wherein the weight % of K.sub.2 O is not smaller than the weight % of Na.sub.2 O.

Abstract: A sintered high-toughness alumina-based composite body comprises a plate- or rod-like, corundum or alumina-based compound structure and another structure having a fine granular corundum structure and containing inevitable impurities. A sintered high-toughness alumina-based composite can be produced by mixing a crystal-growth-promoting additive with a first portion of alumina powder to prepare a mix A, mixing a crystal-growth-inhibiting additive with a second portion of alumina powder to prepare a mix B, granulating at least one of the mix A and the mix B into granules, mixing the mix A and the mix B into a mix C, forming tile mix C into a green body, and then firing the green body, whereby crystals of the corundum or alumina-based compound in the mix A are allowed to grow.

Abstract: A refractory mix made comprising magnesite having an MgO content of at least about 95 wt. % and fused spinel-zirconia grain comprising 1 to 40 wt. % zirconia and refractory shapes, particularly brick, made therefrom.

Abstract: A platelet .alpha.-Al.sub.2 O.sub.3 based ceramic composite consists of Al.sub.2 O.sub.3 powder, promoters and controllers. The composite is prepared by mixing aluminum oxide powder with promoters and controllers. The mixture is shaped and sintered to form an object. In one embodiment of the invention, the promoters are either salts or oxides of alkaline metals and alkaline earth metals. The salts are oxidized during sintering.

Abstract: A method of producing an electrocast brick or other ceramic shape, and the ceramic shape produced thereby, wherein the electrocast brick or other ceramic shape is cast in a mold which is formed, with a predetermined cavity shape and size, of quartz glass particles; the ceramic material of the ceramic shape may be Al.sub.2 O.sub.3 -ZrO.sub.2 -SiO.sub.2 ceramic, Al.sub.2 O.sub.3 -SiO.sub.2 ceramic or other heat meltable ceramic materials.

Abstract: Disclosed is a phenol-formaldehyde resin binder for refractories, having from 0.05 to 0.6 methylol group on average per one phenolic constitutive unit and having a free phenol content of less than 5%. For producing refractory granules with the binder, a composition comprising carbon substances of 50% by weight or less in all and a balance of refractory substances is kneaded with the binder and water optionally along with a solvent having a boiling point of 200.degree. C. or higher, in a mixer as heated at 60.degree. to 130.degree. C. Optionally, the volatile content in the blended mix is adjusted to the shapable level. The process of using the binder is free from injury to human bodies and the danger of firing. The refractory granules may be shaped into refractory articles having a suitable gas-permeability stable against variation of the working environment. The refractory granules are suitable for shaping gas-blowing immersion nozzles having a suitable gas-permeability.

Abstract: A refractory article such as a slide gate plate, well block nozzle or like refractory component used in continuous casting of chemically aggressive grades of steel is made from a mixture containing about 50-85 wt. % alumina; about 5-30 wt. % alumina-zirconia fused grain; about 3-10 wt. % zirconia; and about 3-10 wt. % silica, plus an effective amount of binder materials to permit extrusion, pressing or like forming process. The pressed shape is fired in an air atmosphere at temperatures in excess of 1000.degree. C. to form an oxide bond. The composition of the fired material comprises about 60-90 wt. % alumina; about 5-30 wt. % zirconia; and about 3-10 wt. % silica. The fired article exhibits excellent hot strength and is resistant to thermal shock and resistant to the erosive and corrosive effects of molten steel, including aggressive, high manganese and calcium treated grades.

Abstract: In ceramic welding processes, oxidizing gas and a mixture of refractory and fuel powders are projected against a surface and the fuel is burnt to generate sufficient heat that the refractory powder becomes at least partially melted or softened and a cohesive refractory weld mass is progressively built up against that surface. In order to reduce any tendency for the weld mass to include a low-grade refractory phase and thus promote the refractoriness of that weld mass, the fuel powder is present in a proportion of not more than 15% by weight of the total mixture and includes at least two metals selected from aluminum, magnesium, chromium and zirconium, in that at least the major part by weight of the refractory powder consists of one or more of magnesia, alumina and chromic oxide, and in that the molar proportions of silica and calcium oxide present in the refractory powder (if any) satisfy the following expression:molar concentration of SiO.sub.2 in %.ltoreq.0.2+molar concentration of CaO in %.

Abstract: Translucent polycrystalline alumina made of aluminum oxide containing magnesium oxide in an amount of larger than 0.01% by weight and less than 0.03% by weight, zirconium oxide in an amount of larger than 0.01% by weight and less than 0.06% by weight and calcium oxide in an amount of less than 0.001% by weight, all based on the weight of aluminum oxide, which alumina has good light transmittance and mechanical strength.

Abstract: A slide gate plate comprising a burned refractory that is impregnated with tar and baked, said refractory made from a composition comprising about 70 to 95 wt. % alumina, 1 to 10 wt. % reactive alumina, 1 to 5 wt. % volatilized silica, and, 3 to 15 wt. % silicon carbide and the method of increasing the service life of such slide gate plate by forming the same from the above-noted composition.

Abstract: The present invention pertains to a refractory casting slip consisting of a refractory matrix material and a finely divided reactive component, as well as a hydraulic binder and various additives, which can be discharged as a free-flowing mass upon addition of water.

Abstract: A high zirconia fused cast refractory which comprises from 90 to 95% by weight of ZrO.sub.2, from 3.5 to 7% by weight of SiO.sub.2, from 1.2 to 3% by weight of Al.sub.2 O.sub.3 and from 0.1 to 0.35% by weight in a total amount of Na.sub.2 O and/or K.sub.2 O, and which does not substantially contain any one of P.sub.2 O.sub.5, B.sub.2 O.sub.3 and CuO.

Abstract: A powder for sintering is prepared by the wet mixing of a finely and uniformly divided alumina powder of high purity having a primary particle diameter not exceeding 0.15 micron and an average particle diameter not exceeding 0.3 micron, and a partially stabilized zirconia powder of high purity having an average particle diameter not exceeding 0.3 micron. After granulation and molding, the mixed powder is sintered at a temperature of 1300.degree. C. to 1500.degree. C. to make a sintered body having an average grain size not exceeding 0.7 micron.