Chromium oxide product
AssigneeSaint-Gobain Centre De Recherches Et D'Etudes Europeen
InventorsNicolas Raffin, Laurie San Miguel
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Abstract
A sintered refractory product having a granulate bonded by a matrix and comprising, in percentages by mass based on the oxides, —more than 40% chromium oxide Cr2O3, —less than 50% aluminium oxide Al2O3, −1% or more zirconium oxide ZrO2, of which at least 20% by mass is stabilised in the cubic and/or quadratic form, −0.1% or more yttrium oxide Y2O3, acting as a stabiliser for the zirconium oxide ZrO2, —less than 1.9% hafnium oxide HfO2, the total content of chromium, aluminium and zirconium oxides Cr2O2+Al2O3+ZrO2 being greater than 70%.
Claims24
A sintered refractory product exhibiting an aggregate bonded by a matrix wherein the sintered refractory product comprises, as percentages by weight on the basis of the oxides:
- more than 40% of chromium oxide Cr2O3,
- less than 50% of aluminum oxide Al2O3,
- 1% or more of zirconium oxide ZrO2, at least 20% by weight of which is stabilized in the cubic and/or tetragonal form,
- 0.1% or more and less than 2.0% of yttrium oxide Y2O3, acting as stabilizer for the zirconium oxide ZrO2,
- less than 1.9% of hafnium oxide HfO2,
- the total content of chromium oxide, aluminum oxide and zirconium oxide Cr2O3+Al2O3+ZrO2 being greater than 70%,
- said product comprising a codopant, acting or not acting as stabilizer for the zirconium oxide, selected from the group consisting of CaO, MgO, TiO2, and mixtures thereof, a sum of the contents of calcium oxide, magnesium oxide, and titanium oxide Cao+MgO+TiO2 being less than 6.0% and greater than 0.5%, as percentages by weight, and more than 50% of the yttrium oxide and of the codopant being present in the matrix, as percentage by weight.
Dependencies are inferred from the claim text.