Sintered Al.sub.2 O.sub.3 material, process for its production and use of the material
DC CAFCFirst Claim
Patent Images
1. A method, comprising the steps of:
- a) dispersing α
-Al2 O3 powder having a mean particle size d50 of ≦
0.30 μ
m and a chemical purity of ≧
99.9% α
-Al2 O3 in an aqueous solution to create a mixture, said mixture effected through the application of at least two different dispersing methods;
b) treating said mixture so as to create a shaped unsintered body having a relative density of p≧
55%;
c) heating said unsintered body; and
d) sintering said unsintered body so as to create a sintered material.
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Litigations
4 Petitions
Accused Products
Abstract
The invention relates to the field of ceramics and concerns sintered Al.s2 O3 compositions produced from corundum powder and also methods for the use of the invented compositions as medical implants or tool material. To produce such materials, an initially unsintered precursor having a relative density of ρ≧55% is produced from α-Al2 O3 powder having defined properties using at least two different dispersing methods, this precursor is subsequently subjected to heat treatment and sintering.
78 Citations
53 Claims
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1. A method, comprising the steps of:
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a) dispersing α
-Al2 O3 powder having a mean particle size d50 of ≦
0.30 μ
m and a chemical purity of ≧
99.9% α
-Al2 O3 in an aqueous solution to create a mixture, said mixture effected through the application of at least two different dispersing methods;b) treating said mixture so as to create a shaped unsintered body having a relative density of p≧
55%;c) heating said unsintered body; and d) sintering said unsintered body so as to create a sintered material. - View Dependent Claims (3, 4, 5, 6, 30, 31, 32, 33, 34, 35, 36)
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2. A method, comprising the steps of:
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a) dispersing α
-Al2 O3 powder having a mean particle size d50 of ≦
0.30 μ
m and a chemical purity of ≧
99.9% Al2 O3 in an aqueous solution comprising water, polyvinyl alcohol and glycerol to create a mixture;b) treating said mixture so as to create a shaped unsintered body having a relative density of p≧
55%;c) heating said unsintered body; and d) sintering said unsintered body so as to create a sintered material.
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7. A method, comprising the steps of:
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a) dispersing α
-Al2 O3 powder having a particle size of d16 greater than 0.065 μ
m, d50 not less than 0.2 μ
m and not greater than 0.4 μ
m, d84 not less than 0.45 μ
m and not greater than 0.8 μ
m, and a chemical purity of ≧
99.9% α
--Al2 O3, in an aqueous solution to create a mixture, said mixture effected through the application of at least two different dispersing methods;b) treating said mixture so as to create a shaped unsintered body having a relative density of p≧
55%;c) heating said unsintered body; and d) sintering said unsintered body so as to create a sintered material. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 37, 38)
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15. A method, comprising the steps of:
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a) dispersing α
-Al2 O3 powder having a mean particle size d50 of ≦
0.30 μ
m and a chemical purity of ≧
99.9% Al2 O3 in an aqueous solution to create a mixture, said dispersing comprising stirring said solution and subsequently milling;b) treating said mixture so as to create a shaped unsintered body having a relative density of p≧
55%;c) heating said unsintered body; and d) sintering said unsintered body so as to create a sintered material. - View Dependent Claims (16, 17, 18)
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19. A method, comprising the steps of:
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a) dispersing α
-Al2 O3 powder having a chemical purity of ≧
99.9% Al2 O3 in an aqueous solution to create a mixture, said dispersing comprising stirring said solution and simultaneously subjecting said solution to ultrasound;b) treating said mixture so as to create a shaped unsintered body; c) heating said unsintered body; and d) sintering said unsintered body so as to create a sintered material. - View Dependent Claims (20, 21, 22, 23, 24)
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25. Sintered Al2 O3 material comprising a mean grain size of 1.5 μ
- m or less, a density of no less than 98.8% of a theoretical density, and a Vickers hardness greater than or equal to 2,160 at a test load from 10 to 100 N, said sintered material having a frequency of inhomogeneities of less than 50×
109 m-2.
- m or less, a density of no less than 98.8% of a theoretical density, and a Vickers hardness greater than or equal to 2,160 at a test load from 10 to 100 N, said sintered material having a frequency of inhomogeneities of less than 50×
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26. Sintered Al2 O3 material comprising a mean grain size of 2.0 μ
- m or less, and a density of no less than 98.8% of a theoretical density, a Vickers hardness greater than or equal to 1,750 at a test load from 10 to 100 N, and a flexural strength of 800 MPa or greater, said sintered material having a dimensionless defect density of less than 30×
10-3. - View Dependent Claims (27, 28, 29)
- m or less, and a density of no less than 98.8% of a theoretical density, a Vickers hardness greater than or equal to 1,750 at a test load from 10 to 100 N, and a flexural strength of 800 MPa or greater, said sintered material having a dimensionless defect density of less than 30×
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39. A method, comprising the steps of:
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a) dispersing α
-Al2 O3 powder having a mean particle size d50 of ≦
0.30 μ
m and a chemical purity of ≧
99.9% α
-Al2 O3, a polymerizable monomer, and a polymerization initiator in an aqueous solution to create a mixture, wherein said mixture has a solids content of α
-Al2 O3 powder of greater than 60% by mass, said mixture effected through the application of at least two different dispersing methods;b) treating said mixture by degassing said mixture under a reduced pressure of 100-300 mbar, and initiating polymerization of said polymerizable monomer through the addition of a catalyst or increasing the temperature to 55-80 degrees Celsius so as to create an unsintered body having a relative density of p≧
55%;c) heating said unsintered body; and d) sintering said unsintered body so as to create a sintered material. - View Dependent Claims (40, 41, 42, 43, 44)
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45. A method, comprising the steps of:
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a) dispersing α
-Al2 O3 powder having a mean particle size d50 of ≦
0.30 μ
m and a chemical purity of ≧
99.9% α
-Al2 O3 in an aqueous solution to create a mixture, said dispersing of said α
-Al2 O3 powder effected through the application of at least two different dispersing methods;b) treating said mixture so as to create a shaped unsintered green intermediate product having a relative density of p≧
55%;c) heating said unsintered green intermediate product so as to create an unsintered precursor; d) crushing said unsintered precursor; and e) sintering said crushed unsintered precursor so as to create a sintered material. - View Dependent Claims (46, 47, 48, 49, 50, 51)
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52. A method, comprising the steps of:
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a) dispersing α
-Al2 O3 powder having a mean particle size d50 of ≦
0.30 μ
m and a chemical purity of ≧
99.9% α
-Al2 O3 in an aqueous solution to create a mixture, said mixture effected through the application of at least two different dispersing methods;b) treating said mixture with a pressure process so as to create an unsintered precursor having a relative density of p≧
55%;c) heating said unsintered precursor; and d) sintering said unsintered precursor so as to create a sintered material. - View Dependent Claims (53)
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Specification