Abstract: A sintered ceramic foam that has a total porosity of greater than 60% by volume and the following phase composition, in mass percent based on the crystallized phases: 25 to 55% mullite, 20 to 65% corundum, 10 to 40% zirconia, mullite, corundum and zirconia together representing more than 80% of the mass of the crystallized phases. Also, a furnace that has a thermal insulator such ceramic foam.

Abstract: The present invention relates to a method for forming a ceramic coating having improved plasma resistance and a ceramic coating formed thereby. The present invention discloses the method for forming the ceramic coating having improved plasma resistance and the ceramic coating formed thereby, comprising the steps of: receiving, from a powder supply portion, a plurality of ceramic powders having a first powder particle size range, and transporting the powders using a transport gas; and forming a ceramic coating in which a plurality of first ceramic particles within a first coating particle size range and a plurality of second ceramic particles within a second coating particle size range, which is larger than the first coating particle size range, by causing the transported ceramic powders to collide with a substrate inside a process chamber, at the speed of 100 to 500 m/s so as to be pulverized.

Abstract: A zirconia sintered body contains aluminum, cobalt, and manganese and a remaining portion consisting of yttria-containing zirconia. In an oxide exchange, aluminum content is 5.0 wt % or more and 30.0 wt % or less, cobalt content is 0.1 wt % or more and 2.0 wt % or less, and manganese content is 0.5 wt % or more and 7.0 wt % or less.

Abstract: The invention relates to a fused cast refractory material based on aluminium oxide, zirconium dioxide and silicon dioxide, and a use of such a material.

Abstract: The invention refers to a method for producing means with thermal resist for applying at a surface of a heat exposed component. The method includes providing at least one mixture of at least two different inorganic powder materials: with different chemical composition and thermal expansion coefficient, where at least one of the powder materials experiences volume changes due to crystallographic phase change at a given temperature, and/or\ where at least one of the two powder materials experiences volume changes due to chemical composition change, forming the at least one mixture into a green body shape, sintering the green body to obtain a ceramic body and cooling the ceramic body and causing micro-cracking during heating and or/sintering and/or cooling to obtain the means with thermal resist. The forming is performed such that a first mixture forming a first layer onto which a second mixture is applied forming a second layer differs in porosity from that first layer to obtain a layered green body.

Abstract: A refractory object may include a zircon body that may include at least about 0.1 wt. % and not greater than about 5.5 wt. % of an Al2O3 containing component for a total weight of the zircon body. The zircon body may further include at least about 25 wt. % and not greater than about 35 wt. % of a SiO2 component for a total weight of the zircon body.

Abstract: Methods are described to make strong, tough, and lightweight whisker-reinforced glass-ceramic composites through a self-toughening structure generated by viscous reaction sintering of a complex mixture of oxides. The invention further relates to strong, tough, and lightweight glass-ceramic composites that can be used as proppants and for other uses.

Abstract: A ceramic composite material and a method for producing same. The ceramic composite material has a ceramic matrix comprising zirconium oxide and at least one secondary phase dispersed therein. The matrix is composed of zirconium oxide as at least 51 vol.-% of composite material, and the secondary phase is in a proportion of 1 to 49 vol.-% of composite material, wherein 90 to 99% of the zirconium oxide is present in the tetragonal phase based on the total zirconium oxide portion. The tetragonal phase of the zirconium oxide is stabilized by at least one member selected from the group consisting of chemical stabilization and mechanical stabilization. The ceramic composite is damage-tolerant.

Abstract: A method and device for chemical destruction of at least one feed comprising at least one organic compound are provided. The device comprises at least one inductive plasma torch, means for introducing at least one plasma-forming gas into the torch, optionally when the plasma gas(es) comprise(s) no or little oxygen, means for bringing oxygen gas into the plasma or into the vicinity of the plasma, means for introducing the feed into the torch, a reaction enclosure capable of allowing thermal destruction of the gases flowing from the torch, a device allowing mixing of the gases flowing out of the reaction enclosure to be carried out, means for introducing air and/or oxygen gas into the mixing device, a device allowing recombination by cooling of at least one portion of the gases from the mixing device, the torch, the reaction enclosure, the mixing device and the recombination device being in fluidic communication.

Abstract: The present invention relates to flaky aluminum oxide and a preparation method thereof, and more particularly, to a flaky aluminum oxide which is suitably used as a substrate for a pearlescent pigment or the like, and to a preparation method thereof.

Abstract: The invention relates to a metal-ceramic substrate and to a method for the production thereof, the substrate including at least one ceramic layer having first and second surface sides, at least one of the surface sides of which is provided with a metallization, wherein the ceramic material forming the ceramic layer contains aluminum oxide, zirconium dioxide and yttrium oxide. The ceramic layer contains aluminum oxide, zirconium dioxide and yttrium oxide in the following proportions, in each case in relation to the total weight thereof: zirconium dioxide between 2 and 15 percent by weight; yttrium oxide between 0.01 and 1 percent by weight; and aluminum oxide between 84 and 97 percent by weight, wherein the average grain size of the aluminum oxide used is between 2 and 8 micrometers and the ratio of the length of the grain boundaries of the aluminum oxide grains to the total length of all the grain boundaries is greater than 0.6.

Abstract: A catalyst for purification of exhaust gas, comprising a first catalyst comprising: a first catalyst support comprising a first composite oxide composed of alumina, zirconia, and titania, and ceria supported on a surface of the first composite oxide in an amount of 0.5 to 10 parts by mass relative to 100 parts by mass of the first composite oxide; and a first noble metal supported on a surface of the first catalyst support in an amount of 0.05 to 5.0 parts by mass in terms of metal relative to 100 parts by mass of the first catalyst support.

Abstract: In a ceramic composition mainly composed of alumina (Al2O3), tungsten carbide (WC) and zirconia (ZrO2), zirconium (Zr) is distributed in a first grain boundary as an interface where an alumina (Al2O3) crystal grain is adjacent to a tungsten carbide (WC) crystal grain and in a second grain boundary as an interface where two alumina (Al2O3) crystal grains are adjacent to each other.

Abstract: A handle substrate 1 is made of a translucent ceramics. An average density of pores having a size of 0.5 to 3.0 ?m included in a surface region 2A on the side of a bonding face 1a of the handle substrate 1 is 50 counts/mm2 or smaller. It is formed a region 3, whose average density of pores having a size of 0.5 to 3.0 ?m is 100 counts/mm2 or larger, in the handle substrate 1. The translucent ceramics has an average grain size of 5 to 60 ?m.

Abstract: It is provided a handle substrate of a composite substrate for a semiconductor. The handle substrate is composed of a translucent polycrystalline alumina. A purity of alumina of the translucent polycrystalline alumina is 99.9% or higher, an average of a total forward light transmittance of the translucent polycrystalline alumina is 60% or higher in a wavelength range of 200 to 400 nm, and an average of a linear light transmittance of the translucent polycrystalline alumina is 15% or lower in a wavelength range of 200 to 400 nm.

Abstract: The invention relates to a composite ceramic material which comprises: (a) a first phase based on zirconia containing CeO2 as stabilizer, and (b) a second phase based on an aluminate. The invention also relates to a ceramic powder composition, processes for the preparation of the composite ceramic material and the ceramic powder composition as well as uses thereof.

Abstract: The present invention relates to a fused refractory product having the following average chemical composition, as a percentage by weight on the basis of the oxides and for a total of 100%: ZrO2: 60.0%-80.0%; SiO2: 4.0%-10.0%; Al2O3: balance to 100%; Y2O3?5.0%; Na2O+K2O+B2O3?0.3% and SiO2/(Na2O+K2O+B2O3)?5.0; other oxide species: ?2.0%; the ratio of the ZrO2/Al2O3 weight contents being between 2.0 and 6.0.

Abstract: The invention relates to a communication device using radio waves with frequencies of 800 MHz to 3 GHz, comprising a ceramic cover at least partially exposed to the external environment of the device, at least one portion of said waves passing therethrough during the use of the device, said cover being at least partially made of a sintered product having a chemical composition such as, by weight and for a total of 100%, 32%?ZrO2?95%, 1%<Y2O3+CeO2+Sc2O3+MgO+CaO, 0%?CeO2?26%, 0%?MgO?43%, 0%?CaO?37%, 0%?SiO2?41%, 0%?Al2O3?55%, 0%?TiO2?30%, 0%?lanthanide oxide, except for CeO2?50% 0% SrO?24%, o %?iAlON compounds ?50%, and other compounds ?15%.

Abstract: A fused refractory product having the following average chemical composition, in % by weight on the basis of oxides and for a total of 100%: ZrO2: 30-50%; SiO2: 8-16%; Al2O3: balance to 100%; Y2O3?50/ZrO2 and Y2O3?5%; Na2O+K2O+B2O3?0.2% and SiO2/(Na2O+K2O+B2O3)?5×Y2O3; CaO: ?0.5%; and other oxide species: ?1.5%.

Abstract: An insulator for spark plug with a main constituent of alumina and containing silicon includes a grain boundary phase positioned between alumina particles. The grain boundary phase contains: a group 2A element; a rare earth element; and at least one kind of zirconium, titanium, chrome, niobium, manganese, and iron (a first element). Assuming that a total amount of the rare earth element is X (mass %), a total amount of the group 2A element is Y (mass %), and a total amount of the first element is Z (mass %), the following are met: 0.40?Y/X?2.00 0.10?Z/X?0.40.

Abstract: An electronic component element housing package is produced by firing a ceramic substrate for housing an electronic component element and a metal layer for bonding to the ceramic substrate to form an electrical path, simultaneously in a reducing atmosphere. The ceramic substrate comprises alumina (Al2O3), a partially stabilized zirconia by forming solid solution with yttria (Y2O3) and a sintering agent. The sintering agent comprises magnesia (MgO), and at least 1 type selected from silica (SiO2), calcia (CaO), or manganese oxides (MnO, MnO2, Mn2O3, Mn3O4).

Abstract: The present application is directed to a zirconia toughened alumina body and process for making the body. The process involves combining tetragonally stabilized ZrO2 nanoparticles, Mg(OH)2 particles and alumina powder into a mixture. All particles of the mixture are milled, formed into a green compact and then sintered. The final composition of the body includes ?-Al2O3 toughened with 0.5 to 2.5 weight percent ZrO2 in a stabilized tetragonal form and 0.03 to 0.10 weight percent MgO. The composition results in an Al2O3 body with a density less than 4.0 g/cc and strength greater than 50 kpsi.

Abstract: Methods and a kit. A cement forming method includes nucleating an acidic metallophosphate reaction mixture with first particles, resulting in forming a settable metallophosphate cement from the acidic metallophosphate reaction mixture. The first particles include a first metal oxide. Each particle of the first particles independently have a particle size in a range from about 15 microns to about 450 microns. A method for applying cement includes seeding a solution with particles, resulting in forming a settable cement from the solution. The particles have a size in a range from about 15 microns to about 450 microns. The solution includes a first metal oxide reacting with phosphate. The settable cement is applied to a substrate. A cement application kit is also described.

Abstract: Shape memory and pseudoelastic martensitic behavior is enabled by a structure in which there is provided a crystalline ceramic material that is capable of undergoing a reversible martensitic transformation and forming martensitic domains, during such martensitic transformation, that have an elongated domain length. The ceramic material is configured as a ceramic material structure including a structural feature that is smaller than the elongated domain length of the ceramic material.

Abstract: There is disclosed a porous material. The porous material contains aggregates, and a bonding material which bonds the aggregates to one another in a state where pores are formed among the aggregates, the bonding material contains crystalline cordierite, the bonding material further contains a rare earth element or a zirconium element, and a ratio of a mass of the bonding material to a total mass of the aggregates and the bonding material is from 12 to 45 mass %. The bonding material preferably contains, in the whole bonding material, 8.0 to 15.0 mass % of MgO, 30.0 to 60.0 mass % of Al2O3, 30.0 to 55.0 mass % of SiO2, and 1.5 to 10.0 mass % of a rare earth oxide or zirconium oxide.

Abstract: A sintering composition and calcined object which are precursors for a sintered zirconia. The burned surface of the sintered zirconia gives an X-ray diffraction pattern in which the ratio of the height of the peak present around the location where a [200] peak assigned to the cubic system is to appear to the height of the peak present around the location where a [200] peak assigned to the tetragonal system is to appear is 0.4 or more, and a region located at a depth of 100 ?m or more from the burned surface gives an X-ray diffraction pattern in which the ratio of the height of the peak present around the location where a [200] peak assigned to the cubic system is to appear to the height of the peak present around the location where a [200] peak assigned to the tetragonal system is to appear is 0.3 or less.

Abstract: It is an object of the present invention to provide a sintered cBN compact having excellent wear resistance and fracture resistance even in machining centrifugally cast iron having a property of being difficult to machine, and to provide a sintered cBN compact tool. A sintered cBN compact of the present invention contains 20% by volume or more and 65% by volume or less of cBN and, as a binder, 34% by volume or more and less than 80% by volume of Al2O3, at least one selected from the group consisting of nitrides, carbides, carbonitrides, borides, and boronitrides of Zr and solid solutions thereof (hereinafter, referred to as “X”), and ZrO2, the total amount of X and ZrO2 being 1.0% by volume or more and 6.0% by volume or less, the volume ratio of ZrO2 to Al2O3, ZrO2/Al2O3, being 0.010 or more and less than 0.100, in which the ratio Itetragonal ZrO2(101)/I?Al2O3(110) is 0.

Abstract: To provide a high zirconia fused cast refractory having high durability, which hardly has cracks at the time of production of the refractory, during the heating, by temperature changes during use and during the cooling at the time of suspension of operation. A high zirconia fused cast refractory which has a chemical composition comprising from 88 to 96.5 mass % of ZrO2, from 2.5 to 9.0 mass % of SiO2, from 0.4 to 1.5 mass % of Al2O3, from 0.07 to 0.26 mass % of Na2O, from 0.3 to 1.3 mass % of K2O, from 0 to 0.3 mass % by outer percentage of Li2O, at most 0.08 mass % by outer percentage of B2O3, and at most 0.08 mass % by outer percentage of P2O5, and contains B2O3+P2O5 in a content of at most 0.1 mass % by outer percentage.

Abstract: Hardness, ageing resistance, wetting behavior in relating to water and high thermal conductivity are known characteristics of sintered molded bodies consisting of aluminum oxide; high strength and a high resistance to cracking, i.e., damage tolerance are known characteristics of sintered molded bodies consisting of zirconium oxide. These properties are combined in a material having a large fraction of aluminum oxide, zirconium oxide and optionally strontium aluminate.

Abstract: A material composed of a large fraction of aluminum oxide, zirconium oxide and strontium aluminate.

Abstract: The present invention provides a ceramic material comprising: a first phase comprising zirconia, yttrium and cerium, wherein the yttrium and cerium are present in a molar ratio of 0.15 to 0.5 and in a combined amount of 5 to 15 mol %, a second phase comprising alumina, and a third phase comprising metal aluminate platelets.

Abstract: A ceramic sintered body includes tungsten carbide, zirconia, and alumina. The content of the tungsten carbide is 20 to 50 vol %, and the content of the zirconia is 5 to 25 vol %. The crystal phase of the zirconia is a tetragonal crystal or a mixture of tetragonal and monoclinic crystals. The ceramic sintered body does not substantially include Ti compounds. The average particle diameter of the tungsten carbide, the average particle diameter of the zirconia, and the average particle diameter of the alumina are all 1 ?m or less.

Abstract: The invention relates to a powder comprising more than 70% of refractory particles, in weight percent relative to the weight of the powder, a particle of said powder being classed in the fraction called “matrix” or in the fraction called “aggregate”, according to whether it is smaller than, or equal to 100 ?m, or larger than 100 ?m, respectively, said powder comprising, in weight percent relative to the weight of the powder: between 0.1% and 18% of particles of a heat-activatable binder, called “heat-activatable binder particles”; and more than 40% of refractory particles, called “ATZ particles”, having the following chemical composition, in weight percentages on the basis of the oxides of said ATZ particles: 10%?Al2O3?55%; 35%?TiO2?80%; 1%?MgO+Cr2O3?10%; 8%?ZrO2?20%; SiO2?8%.

Abstract: The invention relates to a composite ceramic material which comprises: (a) a first phase based on zirconia containing CeO2 as stabilizer, and (b) a second phase based on an aluminate. The invention also relates to a ceramic powder composition, processes for the preparation of the composite ceramic material and the ceramic powder composition as well as uses thereof.

Abstract: A sintered body containing alumina crystal particles and zirconia crystal particles as main components includes the tetragonal crystal particles as the zirconia crystal particles. The zirconia crystal particles satisfy relations 0%?A?3%, 3%?B?22% and 77%?C?96%,where A, B and C are as defined herein.

Abstract: Specialty ceramic materials which resist corrosion/erosion under semiconductor processing conditions which employ a corrosive/erosive plasma. The corrosive plasma may be a halogen-containing plasma. The specialty ceramic materials have been modified to provide a controlled electrical resistivity which suppresses plasma arcing potential.

Abstract: The present invention relates to a molten, fluid refractory product comprising, in weight percentages on the basis of the oxides and for a total of 100% of the oxides: ZrO2+Hf2O: remainder to 100% 4.5%<SiO2<6.0% Al2O3<0.80% 0.3%<B2O3<1.0% Ta2O5+Nb2O5<0.15% Na2O+K2O<0.1% K2O<0.04% CaO+SrO+MgO+ZnO+BaO<0.4% P2O6<0.05% Fe2O3+TiO2<0.55% other oxide species, optionally including Y2O3: <1.5%, where Y2O3<0.3%, the “A/B” ratio of Al2O3/B2O3 content by weight being 0.5 to 2.0. The invention can be used in glass melting furnaces.

Abstract: The present invention relates to a molten, fluid refractory product comprising, in weight percentages on the basis of the oxides and for a total of 100% of the oxides: ZrO2+Hf2O: remainder to 100% 4.0%<SiO2<6.5% Al2O3?0.75% 0.2%<B2O3<1.5% 0.3%<Ta2O5 Nb2O5+Ta2O5<1.4% Na2O+K2O<0.2% BaO<0.2% P2O5<0.15% Fe2O3+TiO2<0.55% other oxide species: <1.5% the “A/B” ratio of Al2O3/B2O3 content by weight being no higher than 1.50. The invention can be used in glass melting furnaces.

Abstract: A thermal spray powder of the present invention contains a rare earth element and a diluent element that is not a rare earth element or oxygen, which is at least one element selected, for example, from zinc, silicon, boron, phosphorus, titanium, calcium, strontium, and magnesium. A sintered body of a single oxide of the diluent element has an erosion rate under specific etching conditions that is no less than 5 times the erosion rate of an yttrium oxide sintered body under the same etching conditions.

Abstract: The invention relates to a molten cast refractory product comprising, in weight percentages on the basis of the oxides and relative to a total of 100% of the oxides: ZrO2+Hf2O is the remainder making up 100%, 4.5%<SiO2<6.0%, 0.80%?Al2O3<1.10%, 0.3%<B2O3<1.5%, Ta2O5+Nb2O5<0.15%, Na2O+K2O<0.1%, K2O<0.04%, CaO+SrO+MgO+ZnO+BaO<0.4%, P2O5<0.05%, Fe2O3+TiO2<0.55%, and other oxide species <1.5%, the “A/B” ratio of the Al2O3/B2O3 contents by weight being between 0.75 and 1.6. The invention can be applied to glass melting furnaces.

Abstract: The present invention relates to a fused refractory product having the following average chemical composition, as a percentage by weight on the basis of the oxides and for a total of 100%: ZrO2: 60.0%-80.0%; SiO2: 4.0%-10.0%; Al2O3: balance to 100%; Y2O3?5.0%; Na2O+K2O+B2O3?0.3% and SiO2/(Na2O+K2O+B2O3)?5.0; other oxide species: ?2.0%; the ratio of the ZrO2/Al2O3 weight contents being between 2.0 and 6.0.

Abstract: To provide a high zirconia fused cast refractory which has high corrosion resistance to molten glass and which is scarcely susceptible to cracking during its production. A high zirconia fused cast refractory which has a chemical composition comprising from 96.5 to 98.5 mass % of ZrO2, from 0.8 to 2.7 mass % of SiO2, from 0.04 to 0.35 mass % in a total amount of Na2O and K2O, and from 0.02 to 0.18 mass % of B2O3, wherein contents of Na2O, K2O and B2O3 satisfy the relation of the following formula (1) at the same time: 0.03?CB2O3?(CNa2O+CK2O)??(1) wherein CNa2O is the content of Na2O, CK2O is the content of K2O, and CB2o3 is the content of B2O3, and each of these contents represents mass % in the refractory.

Abstract: Shot blasting particles are constituted by a ceramic material having an apparent relative density of more than 4.0 and less than 5.0 and comprising more than 5% of silica, as a percentage by weight based on the oxides.

Abstract: A fused and cast refractory product containing, in weight percentages on the basis of the oxides and for a total of 100%: ZrO2: remainder up to 100% Hf2O: <5% SiO2: 2% to 10% 0.9%<Y2O3+CeO2+CaO+MgO?4.0% B2O3: ?4.5% B2O3: ?0.09×(Y2O3+?(CeO2+CaO+MgO))×SiO2 Al2O3: 0.3% to 2.0% Na2O+K2O: ?0.5% P2O5: <0.05% Fe2O3+TiO2: <0.55% other species: <1.0%, as long as the Y2O3 content is no lower than 0.5% and the CeO2+CaO+MgO content is no lower than 2%.

Abstract: This invention relates to thermally sprayed coatings of a high purity yttria or ytterbia stabilized zirconia powder, said high purity yttria or ytterbia stabilized zirconia powder comprising from about 0 to about 0.15 weight percent impurity oxides, from about 0 to about 2 weight percent hafnium oxide (hafnia), from about 6 to about 25 weight percent yttrium oxide (yttria) or from about 10 to about 36 weight percent ytterbium oxide (ytterbia), and the balance zirconium oxide (zirconia). Thermal barrier coatings for protecting a component such as blades, vanes and seal surfaces of gas turbine engines, made from the high purity yttria or ytterbia stabilized zirconia powders, have a density greater than 88% of the theoretical density with a plurality of vertical macrocracks homogeneously dispersed throughout the coating to improve its thermal fatigue resistance.

Abstract: Dental articles are produced using relatively low sintering temperatures to achieve high density dental articles exhibiting strengths equal to and greater than about 700 MPa. Ceramic powders comprised of nanoparticulate crystallites are used to manufacture dental articles. The ceramic powders may include sintering agents, binders and other similar additives to aid in the processing of the ceramic powder into a dental article. The ceramic powders may be processed into dental articles using various methods including, but not limited to, injection molding, gel-casting, slip casting, or electroforming, hand, cad/camming and other various rapid prototyping methods. The ceramic powder may be formed into a suspension, pellet, feedstock material or a pre-sintered blank prior to forming into the dental article.

Abstract: The present application is directed to a zirconia toughened alumina body and process for making the body. The process involves combining tetragonally stabilized ZrO2 nanoparticles, Mg(OH)2 particles and alumina powder into a mixture. All particles of the mixture are milled, formed into a green compact and then sintered. The final composition of the body includes ?-Al2O3 toughened with 0.5 to 2.5 weight percent ZrO2 in a stabilized tetragonal form and 0.03 to 0.10 weight percent MgO. The composition results in an Al2O3 body with a density less than 4.0 g/cc and strength greater than 50 kpsi.

Abstract: A transparent, polycrystalline ceramic is described. The ceramic comprises crystallites of the formula AxCuByDvEzFw, whereby A and C are selected from the group consisting of Li+, Na+, Be2+, Mg2+, Ca2+, Sr2+, Ba2+, Al3+, Ga3+, In3+, C4+, Si4+, Ge4+, Sn2+/4+, Sc3+, Ti4+, Zn2+, Zr4+, Mo6+, Ru4+, Pd2+, Ag2+, Cd2+, Hf4+, W4+/6+, Re4+, Os4+, Ir4+, Pt2+/4+, Hg2+ and mixtures thereof, B and D are selected from the group consisting of Li+, Na+, K+, Mg2+, Al3+, Ga3+, In3+, Si4+, Ge4+, Sn4+, Sc3+, Ti4+, Zn2+, Y3+, Zr4+, Nb3+, Ru3+, Rh3+, La3+, Lu3+, Gd3+ and mixtures thereof, E and F are selected mainly from the group consisting of the divalent anions of S, Se and O and mixtures thereof, x, u, y, v, z and w satisfy the following formulae 0.125<(x+u)/(y+v)?0.55 z+w=4 and at least 95% by weight of the crystallites display symmetric, cubic crystal structures of the spinel type, with the proviso that when A=C=Mg2+ and B=D=Al3+, E and F cannot both be O.

Abstract: A material composition for producing a fireproof material having a fine-grain fraction with grain sizes of less than 100 ?m and a coarse-grain fraction with grain sizes of more than 100 ?m is provided. The fine-grain fraction includes aluminum oxide having a weight proportion of at least 90% by wt. in relation to the total weight of the fine-grain fraction, zirconium oxide having a weight proportion of up to 5% by wt. in relation to the total weight of the fine-grain fraction, a stabilizer for the zirconium oxide as well as titanium oxide powder having a weight proportion of up to 5% by wt. in relation to the total weight of the fine-grain fractional. The coarse-grain fraction represents a weight fraction of more than 30% by wt. of the material composition.

Abstract: To provide a high zirconia fused cast refractory having high durability, which hardly has cracks during the heating, by temperature changes during use and during the cooling at the time of suspension of operation. A high zirconia fused cast refractory which has a chemical composition comprising from 86 to 96 mass % of ZrO2, from 2.5 to 8.5 mass % of SiO2, from 0.4 to 3 mass % of Al2O3, from 0.4 to 1.8 mass % of K2O, at most 0.04 mass % of B2O3, at most 0.04 mass % of P2O5 and at most 3.8 mass % of Cs2O and containing substantially no Na2O.