Phosphate of calcium ceramics
AssigneeNGK Spark Plugs Co., Ltd.
InventorsAkio Takami, Kazuo Kondo
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Abstract
A strong and biocompatible sintered phosphate of calcium ceramics are obtained by sintering a powdery material substantially consisting of phosphate of calcium having a Ca/P ratio of 1.4-1.75, e.g. apatite group and/or tricalcium phosphate, and not exceeding 15% by weight of CaO-P.sub.2 O.sub.5 frit having a Ca/P ratio of 0.2-0.75. Y.sub.2 O.sub.3 incorporation therein improves the bending strength of the ceramics. Furthermore, a P.sub.2 O.sub.5 -metal oxide frit wherein metal oxide being one or more selected from BaO, CaO, MgO, ZnO, NaO and K.sub.2 O provides a more improved bending strength. The Y.sub.2 O.sub.3 incorporation herein still improves the strength of the sintered product.
Claims26
Phosphate of calcium ceramics obtained by sintering a ceramic material consisting essentially of 3-23% by weight of Y.sub.2 O.sub.3, 0.5-15% by weight of CaO-P.sub.2 O.sub.5 frit having a Ca/P atomic ratio in the range of 0.70-0.75, both calculated for the ceramics, and the balance of a powdery material substantially consisting of phosphate of calcium having a Ca/P atomic ratio of 1.4-1.75, and being of improved bending strength over ceramics otherwise the same but not containing Y.sub.2 O.sub.3.
Phosphate of calcium ceramics obtained by sintering a ceramic material consisting essentially of 3-23% by weight of Y.sub.2 O.sub.3, 0.5-15% by weight of P.sub.2 O.sub.5 -metal oxide frit, both calculated for the ceramics, and the balance of a powdery material consisting essentially of phosphate of calcium having a Ca/P atomic ratio of 1.4-1.75,
- the P.sub.2 O.sub.5 -metal oxide frit consisting essentially of, in mol% calculated for the frit, 40-75% P.sub.2 O.sub.5 and 20-55% of one or more metal oxide selected from the group consisting of BaO, CaO, MgO, ZnO, Na.sub.2 O and K.sub.2 O,
- provided that the sum of said P.sub.2 O.sub.5 and said metal oxide is not less than 90 mol% in the frit and said P.sub.2 O.sub.5 -metal oxide frit in mol% comprises 0-55% BaO, 0-55% CaO, 0-20% MgO, 0-20% ZnO, 0-20% Na.sub.2 O and 0-20% K.sub.2 O, and being of improved bending strength over ceramics otherwise the same but not containing Y.sub.2 O.sub.3.
Dependencies are inferred from the claim text.