Magnetic ball
AssigneeSaint-Gobain Centre De Recherches Et D'Etudes Europeen
InventorsDavid Bouttes, Emmanuel Nonnet
Life of this patent
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Abstract
A sintered ball is provided with the following crystallized phases, in mass percentages based on crystallized phases and for a total of 100%: stabilized zirconia: remainder up to 100%; monoclinic zirconia: ≤20%; 4% ≤magnetic component ≤22%; crystallized phases other than stabilized zirconia, monoclinic zirconia and magnetic component: <10%. The magnetic component is chosen from among magnetic spinels, magnetic garnets, magnetic hexagonal ferrites and mixtures thereof. The sintered ball has, in addition to the magnetic component, CeO2 and optionally Y2O3, in contents that, in molar percentages on the basis of the sum of ZrO2, CeO2 and Y2O3, 3% ≤CeO2≤17.5% and 1.5% ≤Y2O3+(CeO2)/3.5≤5%.
Claims19
A sintered bead comprising the following crystalline phases, as percentages by weight on the basis of the crystalline phases and for a total of 100%:
- stabilized zirconia:
- complement to 100%;
- monoclinic zirconia:
- ≤20%;
- 4% ≤magnetic constituent ≤22%;
- crystalline phases other than stabilized zirconia, monoclinic zirconia and magnetic constituent:
- <10%;
- the magnetic constituent being selected from magnetic spinels, magnetic garnets, magnetic hexagonal ferrites and their mixtures;
- excluding the magnetic constituent, the sintered bead comprising CeO2 and optionally Y2O3 in contents such that 3% ≤CeO2≤17.5% and 1.5% ≤Y2O3+(CeO2)/3.5≤5%, as molar percentages on the basis of the sum of ZrO2, CeO2 and Y2O3.
Dependencies are inferred from the claim text.