Material to Prevent Low Temperature Degradation of Zirconia
First Claim
1. A degradation resistant composition of matter for use in living tissue comprising:
- an yttria-stabilized tetragonal zirconia polycrystal substrate;
a coating of alumina deposited on the substrate, said coating being deposited by ion beam assisted deposition in the presence of the substrate; and
wherein said coating has a total porosity of less than about 1.0 percent.
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Abstract
The invention is directed to a material and a method of producing the material that is unaffected by the low-temperature degradation, humidity-enhanced phase transformation typical of yttria-stabilized zirconia, as well as of yttria-stabilized tetragonal zirconia polycrystalline ceramic (Y-TZP). Because of the high fracture toughness and high mechanical strength, this class of materials is widely used, including as implants, such as for the packaging material for small implantable neural-muscular sensors and stimulators. The destructive phase transformation rate is dramatically reduced by coating the surface of the Y-TZP component with dense alumina by a physical vapor deposition process, preferably ion beam assisted deposition.
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Citations
14 Claims
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1. A degradation resistant composition of matter for use in living tissue comprising:
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an yttria-stabilized tetragonal zirconia polycrystal substrate;
a coating of alumina deposited on the substrate, said coating being deposited by ion beam assisted deposition in the presence of the substrate; and
whereinsaid coating has a total porosity of less than about 1.0 percent. - View Dependent Claims (2, 3, 4, 5)
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6. (canceled)
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12. (canceled)
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13. A degradation resistant composition of matter for use in living tissue, comprising:
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an yttria-stabilized tetragonal zirconia polycrystal substrate;
a moisture resistant coating of alumina deposited on the substrate;
whereinsaid coating has a total porosity of less than about 1.0 percent. - View Dependent Claims (14)
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Specification