The invention concerns a batch for the production of a refractory product, a process for the production of a refractory product, a refractory product as well as the use of a refractory product.

The invention concerns a batch for the production of a refractory product, a process for the production of a refractory product, a refractory product as well as the use of a refractory product.

The present invention relates to abrasive zirconium corundum grains based on Al.sub.2O.sub.3 and ZrO.sub.2 that have been melted in an electrical arc furnace and have a content ofAl.sub.2O.sub.3 between 52% and 62% by weight,ZrO.sub.2 (+HfO.sub.2) between 35.0% and 45.0% by weight, where a total of at least 80% by weight of the ZrO.sub.2, based on the total content of ZrO.sub.2, is in the tetragonal and/or cubic high-temperature modification,Si compounds of more than 0.8% by weight, expressed as SiO.sub.2,carbon between 0.03% and 0.5% by weight,additives between 0.5% and 10% by weight andraw material-related impurities of less than 3% by weight, where the raw material base for the abrasive grains comprises aluminum oxide, baddeleyite and zircon sand.

A turbine engine part includes at least a substrate, and present on the substrate, a ceramic coating for protection against calcium and magnesium aluminosilicates, the ceramic coating including Al.sub.2O.sub.3 at a molar content lying in the range 33% to 49%, Y.sub.3Al.sub.5O.sub.12 at a molar content lying in the range 21% to 53%, and yttria-stabilized zirconia at a molar content lying in the range 13% to 31%.

A turbine engine part includes at least a substrate, and present on the substrate, a ceramic coating for protection against calcium and magnesium aluminosilicates, the ceramic coating including Al.sub.2O.sub.3 at a molar content lying in the range 33% to 49%, Y.sub.3Al.sub.5O.sub.12 at a molar content lying in the range 21% to 53%, and yttria-stabilized zirconia at a molar content lying in the range 13% to 31%.

The invention relates to mold material mixtures containing an oxide of aluminum and an oxide of zirconium as particulate mixed metal oxide, in combination with refractory mold base materials and a water glass-based binder system. The mold material mixtures, also in the form of multicomponent systems, are used for the production of molds and cores for the foundry industry.

The invention relates to mold material mixtures containing an oxide of aluminum and an oxide of zirconium as particulate mixed metal oxide, in combination with refractory mold base materials and a water glass-based binder system. The mold material mixtures, also in the form of multicomponent systems, are used for the production of molds and cores for the foundry industry.

A process for marking a surface of a refractory ceramic part, known as the surface to be marked. The part has a microstructure of grains including more than 50% by mass of ZrO.sub.2, bound by a silicate binder phase, and a total porosity of less than 5% by volume. The process involves irradiation of the surface with a laser beam. The beam is emitted by a laser device set to comply with relationship: a.V.sup.2+b.F.sup.2+c.VF+d.V+e. F+f<0, in which: a=10.sup.4. D+2?10.sup.6, b=0.5?10.sup.6. D?150?10.sup.6, c=0.5?10.sup.6. D?300?10.sup.6, d=5?10.sup.3. D?2.5?10.sup.6, e=?5?10.sup.3. D+2.0?10.sup.6, and f=?5?10.sup.9. D+1.8?10.sup.12. V is expressed in mm/second, D is expressed in mm and F is expressed in kHz.

A process for marking a surface of a refractory ceramic part, known as the surface to be marked. The part has a microstructure of grains including more than 50% by mass of ZrO.sub.2, bound by a silicate binder phase, and a total porosity of less than 5% by volume. The process involves irradiation of the surface with a laser beam. The beam is emitted by a laser device set to comply with relationship: a.V.sup.2+b.F.sup.2+c.VF+d.V+e. F+f<0, in which: a=10.sup.4. D+2?10.sup.6, b=0.5?10.sup.6. D?150?10.sup.6, c=0.5?10.sup.6. D?300?10.sup.6, d=5?10.sup.3. D?2.5?10.sup.6, e=?5?10.sup.3. D+2.0?10.sup.6, and f=?5?10.sup.9. D+1.8?10.sup.12. V is expressed in mm/second, D is expressed in mm and F is expressed in kHz.

A fused grain having the following chemical composition in percent by weight in relation to the oxides: ZrO.sub.2: 16% to 30%, provided that HfO.sub.2<2%, Al.sub.2O.sub.3: percentage needed to bring the total to 100%, Cr.sub.2O.sub.3: 0.2%, TiO.sub.2: 0.5%, Cr.sub.2O.sub.3+TiO.sub.2: <7%, other elements: <3%, provided that SiO.sub.2+CaO+MgO<1.5%.